Giant Sub-Woofer

PuceBaboon sent us linkage to an amusing story about building a gigantic custom sub woofer. I was about to yawn until I looked at the pictures of them excavating a 60 cubic meter hole, and laying bricks. This one might be a little outside the realm of reasonable, but it's damn impressive.

Comments

The "Biggest"

[winkydink]

The question I have is, "why?" Is the guy making up for some other "shortcoming"?

Re:The "Biggest"

[rokzy]

yeah he was so upset he couldn't get a first post he decided to build this so he couldn't hear himself sobbing.

Re:The "Biggest"

[grub]

I think so, but wouldn't it'd be cheaper to just buy an SUV?

Re:The "Biggest"

[nattt]

The horn is an acoustic transformer that links the cone to the air in the room very effectively. For good results, a bass horn has to be very large, on the scale of the wavelength of the notes it's reproducing.

The bass you hear on your home hi-fi is most likely produced by resonance, something you should avoid if you really want to hear what those bass notes are sounding like. But resonance is cheap! Large bass horns are neither cheap, nor easy, but they sound so much better...

Re:The "Biggest"

[el_salvador]

here are some nice suggestions for its use, people who saw howard stern in private part know what i mean

Re:The "Biggest"

[junklight]

these guys build custom home cinema installations so this was either for a client or I think their own demo to show off what they can do....

Re:The "Biggest"

[winkydink]

By observations, church pipe organs seem to be able to produce some pretty low & loud notes. I don't recall seeing any chambers like this in the cathedrals I've visited

Re:The "Biggest"

[Anonymous Coward]

Perhaps not but you should have seen some very large, very long pipes that accomplish the same function using slightly different principles.

Re:The "Biggest"

[Cheeze]

full-sized church pipe organs are specially tuned. Each pipe plays exactly one note, and the pipe's length determines the wave length. The high ceilings in a church also help.

Re:The "Biggest"

[inburito]

Those pipe organs have pretty darn long pipes (at least the ones I've seen) and have plenty of length to produce fundamental vibrations at low frequencies.

Re:The "Biggest"

[stilwebm]

By observations, church pipe organs seem to be able to produce some pretty low & loud notes. I don't recall seeing any chambers like this in the cathedrals I've visited

That is because pipe organs produce the sound by vibrating the air in the pipe - which you will notice is very long and usually several times wider than the pipes on the other side of the chromatic scale.

Re:The "Biggest"

[Lev13than]

these guys build custom home cinema installations so this was either for a client or I think their own demo to show off what they can do....

I'm still not convinced. Does anyone have an .mp3 recording of the room? I want to hear the difference between that setup and my laptop's speakers.

Re:The "Biggest"

[junklight]

The best thing to do would be to record your laptop and the room on one of those digital voice recorder thingys and then you would be comparing like with like....

Re:The "Biggest"

[Anonymous Coward]

I think one could do *a lot* better by using a DSP to provide motion control on the speaker membrane. It's a DC motor after all!

That way one would only need a damped, closed box and none of this fiddling with physical stuff like horns and reflex ports - instead one needs to tune the filter parameters in the position control algorithm. That can be done on the production line.

If ones audio system is based on a digital amplifier chain, there will be a DSP in there anyway - and it may already be implemented - maybe thats why one can buy very good surround sound systems at a decent price these days.

Re:The "Biggest"

[bowronch]

I'm thinking that if you go to that trouble for acousitc quality, you don't use a lossy compression format...

Also, what are you planning on listening to the mp3's on?

Re:The "Biggest"

[stephenisu]

MUCH MUCH cheaper in fact. Order of magnitude cheaper.

Re:The "Biggest"

[miracle69]

The question isn't "why" but rather, "How long before we see this setup on MTV's Cribs?"

Re:The "Biggest"

[Anonymous Coward]

Way to blow the joke.

Re:The "Biggest"

[blinder]

Actually... with proper use of "bass traps" you can hear real bass out of decent monitors (I'm thinking of nicer monitors... ala Event 20/20's or a nice pair of Tannoy's).

Using bass traps in the corners of the room, which is where low freq's tend to rest can go a long way in ensuring that the low-end you hear is not the room, but the actual sound.

Of course bass traps aren't a "fix-all" good acoustic absorption goes a long way as well to stop the slap-back and other nasty room things.

Ah... but you'd have to be a real freak to convert a room in your house to a recording studio... errr... oh wait... heh :)

Re:The "Biggest"

[da5idnetlimit.com]

Well; the army made some research on low herz weapons...

If I remember, 15 Hz would make you feel all wobbly, and puking, and you had lotsa other effects for every pitch up and down.

I just want to be there when his SubWoofer System will get into RESONANCE WITH HIS HOUSE !!!

With so much power, we will have something like the Horns of the Bible, and the Crumbling walls of Babylon.... /envious I just hope it happens /envious /jealous Can we have a peek AT THE REST OF THE GODDAM HOUSE, PLEASE ??? /jealous

I really wanna see what his Jacuzzi is coming to 8)

Re:The "Biggest"

[Trolling4Dollars]

Regardless of how you control the movement of the cone, there is a limit to how much air the cone will actually disturb, thus limiting the strength of the wave. So,... you might get that shitty 4 inch cone moving at precisely 20 Hz, but it's only going to sound bassy to someon the size of a peanut.

Re:The "Biggest"

[nattt]

Nope - you're removing room resonance, which can be a good thing, but that does nothing for the resonances produced inside the speaker cabinet (or port) that is uses to produce bass. Try a pari of Tannoy westminsters or other large-ish horns and hear the difference.

Re:The "Biggest"

[Technician]

FYI, Church organs go to 32 foot pipes. The good ones go one rank further to 64 feet. These are the big folded pipes in back. You won't get to see these unless they have a viewing window to the real pipes. They are not the pretty pipes in front. The 64 footers are almost always folded double or triple (like most brass insturments) because the pipe loft isn't that tall. Due to the shape of the pipe, it's throat, and other attributes, most pipes don't play exactly one pitch. That's why they don't all sound like sine waves or have a flute sound. Some pipes have brass and trumpet sounds instead of flute sounds. This is due to the harmonics generated by many pipes to give them rich fat sounds by design.

Re:The "Biggest"

[Anonymous Coward]

You, sir, are a perfect example of why electrical engineers don't always make great audio engineers.

Hi-fi audio is all about vibrating air to sound "like" a real performance. If all you think about is the electronics, you are forgetting about the physical properties of the chosen speaker, the way the cabinet affects those properties, the accoustics of room, the precision of human hearing, and the subjective perception of the listener. Audio design is a discipline which demands that one think about not only electronics (although electronics are important), but wave physics, biology, and psychology.

Re:The "Biggest"

[Anonymous Coward]

Also, for some recordings on some systems, room resonance can be nice. A recording of an accoustic in a really dead and dampened studio becomes a performance of an accoustic guitar in your living room.

Re:The "Biggest"

[cluke]

Funny a discussion about the evil effects of low-hertz noise this should come up, NTK had a link just last week to some guy's sound page with a wav file that you can't hear but is supposed to make you go all funny.

Anyone brave enough to try it??

I seem to remember a story about the KLF (nutter musicians of million-quid burning fame) messing around blasting subsonic sounds about and killing cows and such. Doubtless apocryphal, but funny.

Re:The "Biggest"

[blinder]

Nope - you're removing room resonance

Um yeah, that's pretty much the main problem in hearing the room versus hearing the actual sound.

well... i'll take a pair of Genelec's over anything. Perfectly tuned and as sonically pure as any near-field or main-room monitor will get.

having spent a little time in half-way decent studios... and having heard what a nicely tuned room can get you (coupled with a nice set of Tannoy's and Genelec's as the mains), I'd take that over the size any day of the week. Nice tight low-ends, crystal clear high-end and all the definition and transparency in the mid.

Re:The "Biggest"

[Anonymous Coward]

I enjoy visiting my audiophile friends and casually mentioning that whatever song is playing sounds a little clipped in the high end.

Then I go hit on the wife while the guy spends an hour fiddling with the dials and sliders.

Re:The "Biggest"

[dfghjk]

The bulk of the pipes for such an organ are hidden in pipe rooms. The ones you see are decorative, though functional, and only constitute a small percentage.

Re:The "Biggest"

[dfghjk]

You mean that typical bass speakers are operated through their resonant range. That doesn't mean that the bass is "produced by resonance". Since resonance is passive nothing could ever be "produced" by it.

Now, should you avoid it? Of course not. It only matters how they sound (and feel). Bass horns don't necessarily sound much better and certainly not for this reason.

Re:The "Biggest"

[dfghjk]

I don't think that's the reason. In this case the poster is simply uninformed. I think bad audio engineers are like all other bad engineers.

Re:The "Biggest"

[geeber]

Jesus, don't people have a sense of humor around here!?

Re:The "Biggest"

[dfghjk]

What's a DC motor after all? Loudspeakers are typically driven with voice coils. DC doesn't work too well with these but that doesn't matter because audio is an AC thing.

Subwoofers with active feedback are old news. Check out Velodyne.

Whether active feedback helps or not does not eliminate the need for an engineer to be concerned with the cabinet.

Re:The "Biggest"

[CrazyDuke]

You laugh, and yet Bose and their "Wave" radios are still in business.

FYI: They also used to run TV ads on TV where the manufacturer would tout better color/sharpness/etc. People fail to realize they are watching this on their own TV.

Re:The "Biggest"

[nattt]

If you don't want to hear the room, use headphones! But seriously, tannoy etc. make nice studio monitors, but the classics are the big B&W 601 and the Quad elelectrostatics for monitoring classical recordings. Out of all of these, the Quads are the only ones that don't use any kind of resonance to produce their bass sound, and IMHO, still sound the best.

Re:The "Biggest"

[Mochatsubo]

B&W 801's actually.

Re:The "Biggest"

[blinder]

f you don't want to hear the room, use headphones!

Heh, um... if you are in a recording situation... the only use headphones have is for tracking/monitoring. Doing a mix or mastering using headphones? Um, no. Not in a million years :)

Re:The "Biggest"

[inode_buddha]

Although they're in a different class, I used to own 4 Klipsch corner horns which made good use of room effects. 2 of them were in the rear, connected to the center channel. Modifying the house was out of the question, so I was happy with it. A Walkman would easily fill the room with Bach and Strauss. As it is, the 30-watt amps I normally used allowed me to hear the entire piece while I was outside mowing the lawn. Also FWIW I have seen straight (unfolded) bass horns using 20-inch drivers. Even though they were tuned for 1/2 wave, they would literally rattle your ribs from 300 yards distant.

Re:The "Biggest"

[Anonymous Coward]

HDTV-broadcasts still do that. TSN-HD, for example, shows lots of big exciting close up sports shots. I'm watching it on my 13-inch TV where RGB has become RGR, and am unimpressed.

Re:The "Biggest"

[nattt]

No - they use the crappiest speakers they can find for that so they know what it will sound like on your "boom box"!

I think doing a mix just listenting to it on headphones is as bad as just listening to it on your monitors - you should hear it on both.

Re:The "Biggest"

[blinder]

Not exactly. Yes, a reference is always checked on less-than-professional gear... but if you've ever been in a mastering suite... you will often find the finest available professional monitors because accuracy and transparency cannot be achieved using sub-standard gear.

The whole point of this is that in acoustically tuned rooms, (e.g. decent recording studios) is the most accurate way to represent sound.

Re:The "Biggest"

[Anonymous Coward]

OK, this is not the biggest subwoofer. Sorry to say, but that may be the BIGGEST ENCLOSURE, but NOT THE BIGGEST SUBWOOFER. There are 16 subwoofers, each of 18"s. Too bad Audiobahn makes a ~30" subwoofer they call "The Wok", which is bigger than the 18" subs in this ENCLOSURE. Not to mention Clarion at one point made a sub called the Super Dome. I forget the specs on that one but IIRC it was even larger than "The Wok". Title the stories right, and please get the summary correct. It should read "Biggest Wave Guide Subwoofer Enclosure" not "Biggest Subwoofer"

Re:The "Biggest"

[nattt]

Rooms always effect the sound, so you do need to check on headphones. And I'm sure if someone could decide on which monitors are actually the finest, then they'd be bought, but nobody can decide what's best. Although the real bad news is that accuracy and transparency cannot be acheived at any cost - at a recent recording session I attended it was obvious that most of the sound quality didn't make it past the microphones (a pair of the nicest classic tube Neumann's I've seen in a long time).

Re:The "Biggest"

[smokin_juan]

That link is just a 20Hz sine wave - nothing funny about it.
On the other hand, if you pump that file through the sub-woofer of topic you're liable to liquify your bowels... bring a diaper.

Re:The "Biggest"

[Astroboy!]

I just want to be there when his SubWoofer System will get into RESONANCE WITH HIS HOUSE !!!

I wouldn't -- I think I'd rather be outside when it hits resonanace, but not inside, what with the falling bricks and whatnot.

Re:The "Biggest"

[ContraB]

FYI, Church organs go to 32 foot pipes. The good ones go one rank further to 64 feet.

32 foot pipes are the largest commonly found, and even then only on very large instruemts. A 64' pitched rank is exceedingly rare. The only instrument I'm aware of (in the US) with real 64' pipes is the one at the Atlantic City Convention Hall (website: http://www.acchos.org/ ).

The Washington National Cathedral, in DC, has a 64' pitched rank, but if I recall correctly it's electronic (using speakers), not with actual 64' long lengths of pipe.

Bear in mind, a 32' pitch C is already below 20Hz, well below what most people can hear. A 64' pitch is more of an impressive "special effect" than anything else.

Actually, if anyone else can cite another pipe organ with a 64' pitch (US or otherwise), I'd love to hear about it, so I could hear that monster!

Re:The "Biggest"

[OverCode@work]

Why?

Re:The "Biggest"

[Anonymous Coward]

Bullshit.
You hear low frequencies also with your Stomach.
Impossible with Headphones.

Re:The "Biggest"

[damien_kane]

Why should he go out and spend his hard-earned money on a digital audio recorder when simply drawing the sinewaves he hears would suffice?
It would also be much more accurate. He could superimpose the images over a reference drawing of what he believes the sound should look like, and see which one is more off...

Re:The "Biggest"

[Anonymous Coward]

Well, there's your answer.

Re:The "Biggest"

[Anonymous Coward]

"Heh, um... if you are in a recording situation... the only use headphones have is for tracking/monitoring. Doing a mix or mastering using headphones? Um, no. Not in a million years :)"

Not really true.

I used to produce professionally for the BBC and several record lables and I would say that the art of mastering often relies on headphones a lot.
The _real_ art to monitoring is to realise that no single source can give you the true picture, and therefore a good producer listens to the work through several sources. Usually these are

1) Nearfields
2) Main studio mons
3) Tranny (a crappy mono transistor radio at the other side of the room)
4) Cans (standard headphones DT100 etc)
5) Monitor cans ( $500+ Beyers or AKGs)

Often there is a switch on the desk to select each of these monitoring sources, and you will see a good producer flipping furiously between them during a mastering sesh. The headphones are essential for guaging the ambience in the mix without room colouration.

Additionally it depends how well the producer 'knows' the sources. I have personally mastered tracks ONLY on cans which went on to be RAP award winning chart pieces.

Re:The "Biggest"

[timeOday]

Too bad... I'd rather they made these for movie theatres so I could go enjoy it myself. Why should people go pay to sit in a theater when they can watch DVD's on a large flat screen at home? - for exactly this sort of thing, which most of us will never personally own.

Re:The "Biggest"

[crackshoe]

And, oddly enough, you're more likely to be slapped for the former than the latter.

Re:The "Biggest"

[Bastian]

My use for headphones is that I can get extremely high quality sound in some $100 monitors rather than blowing much more for that to get the same quality out of loudspeakers.

Re:The "Biggest"

[Anonymous Coward]

Dude, ditch the improper use of apostrophe's. It makes you look like a really really stupid fucking idiot.

Re:The "Biggest"

[Anonymous Coward]

BYU has two 64 foot pipes. See here:
http://www.geocities.com/uvagonewsletter/ja nuary_2 003_newsletter.htm

Re:The "Biggest"

[blincoln]

a wav file that you can't hear but is supposed to make you go all funny.

If that 20hz sine wave really did anything odd, then there would be a huge problem in the dance and rap scenes because of the 808 kick drum and/or use of subharmonic synthesizers in clubs.

Re:The "Biggest"

[Bob Davis, Retired]

Even with relatively low-powered monitor speakers, I could create patches on my synthesizer that would literally vibrate my apartment building. All the windows would vibrate, the toilets, the walls, everything.

I stopped doing that after a few times out of safety concerns.

Re:The "Biggest"

[dcam]

I'll get back to you on that one. My father is a bit of an organ buff and he should know, although he is more likely to know of European Organs than US ones.

Re:The "Biggest"

[dcam]

OK, off the top of his head he mentioned 2:
1. Sydney Town hall organ, Australia
2. Liverpool Cathedral, England

No doubt there are others.

I know a little about the Sydney Town hall organ (I live in Sydney), in that it uses pneumatic action.

Re:The "Biggest"

[oregonnerd]

Evidently, this is the sort of company where if you have to ask the price, you can't afford it. I scanned through some of their products, and not a price mentioned...

Re:The "Biggest"

[jo42]

Man, just imagine the sound from farting into a microphone hooked up to that speaker system...

Re:The "Biggest"

[Anonymous Coward]

those are 64' ranks. doesn't mean they have any pipes that are really that big. most 64' ranks are made from the harmonic series above that (32', 21 1/3', 16', 12 4/5', etc...)

Oh my

[v_1_r_u_5]

Howard Stern would have a field day with this puppy!

drool...

[Anonymous Coward]

Oh man.. that room with Motorhead's Boneshaker DVD and some Fort Garry Dark Ale.

All that'd be left are greasy, bloody smudges.

Re:drool...

[tolan-b]

the hell with that... you want some jungle if you want to hear the bass :)

Re:drool...

[Zathrus]

Note that you won't get the full range of the subwoofer with a DVD or CD. Both have a bottom limit of 20 Hz, while the sub in question can allegedly output down to 10 Hz flat (and well below that with fall off).

You'd have to use vinyl to get frequencies that low. And have one hell of a damping system for the player to avoid it being shaken by the sound it's reproducing...

Not a vinyl snob (all of my music is on CD and ripped to MP3), but there are technical limitations. Of course, 20 Hz is far lower than most people's stereo systems can reproduce anyway. Below that you can't really hear it... but you can feel it.

Re:drool...

[Tyler Eaves]

Nope. So wrong. CDs are digital waveforms. There's no reason they can't produce any freq down to 0.0000000000000001 hz. It's just that that low you'll get about 1 cycle an hour...

Re:drool...

[_Shorty-dammit]

uh, no, both are capable of DC output, what's wrong with you? Getting 10Hz out of vinyl (turntable rumble doesn't count :P) would be quite the feat, especially with anything other than a pure 10Hz test tone containing no other frequencies.

Re:drool...

[GWTPict]

We're talking Motorhead, you don't want to hear the bass, you want to feel it.

Re:drool...

[SonOfThor]

Bump on the Fort Garry Dark. That shit rules!!!! I wish I could get it here in Ontario though. Can't find it anywhere here. Drink it all the time when I'm in Winnipeg though..

Re:drool...

[DLWormwood]

Note that you won't get the full range of the subwoofer with a DVD or CD. Both have a bottom limit of 20 Hz, while the sub in question can allegedly output down to 10 Hz flat (and well below that with fall off).

Forgive my naivete, but I cannot see how that can be. My understanding of acoustics and digital sampling suggests that a DVD or CD only has a top limit (of 22-24 kHz). Low frequencies, like 10 Hz, are easily represented by almost any digital sampling standard; they are all over the Nyquist frequency of 20 Hz.

Any problem with bass reproduction from a CD or DVD is purely a matter of the amplifier or signal reproduction circuitry between the CD/DVD player and the speaker, not of the medium itself. Or is there something in the Red Book standard that limits the reproduction after the signal is read off the disc?

Re:drool...

[Anonymous Coward]

"Note that you won't get the full range of the subwoofer with a DVD or CD. Both have a bottom limit of 20 Hz"

this is complete bullshit.

Re:drool...

[ebh]

I think what the parent was referring to is the analog side of a CD or DVD player.

Sure, you could take any digitized waveform from DC to the Nyquist limit and feed it to the DACs, but that doesn't mean that the (cheap consumer-grade) DACs could necessarily recreate the analog waveform, nor that any of the downstream electronics could reproduce the analog either. And even if you could, some parts of the system, like the speaker coils, will likely burn out if you run DC or near-DC (at a significant nonzero voltage) through them.

Re:drool...

[Anonymous Coward]

Thing is, you need a heck of an amp to be able to reproduce sounds near 20 Hz (or lower) ... don't believe me? go into a guitar store and play a 5-string bass, play the lowest note on it, and listen to how distorted it gets, even with the nicest amp in the store. Still fun though.

Re:drool...

[turbo_magic_hat]

First time I played Goldie's Timeless (from the CD of the same name) on a decent Hifi with Sub I was virtually blown of my chair :-) 4:07 into the track and Boom!

Re:drool...

[TopherC]

This reminds me of a problem I now have with my turntable. Yes, I still have a few vinyl records which I would happily replace with CD's given the opportunity. Anyway there appears to be a direct DC coupling from the record player through my tuner/amp to my speakers. When I play records, the little wobbles in them translate directly into rather severe visible motion of the speaker's woofers at around 2-10 Hz. I dare not play these recordings too loudly, since I don't really want to be probing the limits of my speaker cones. I obviously need to add some kind of passive highpass filter in this system, but I haven't yet found a good (and cheap) way to do this. I'm sure it's not hard to build yourself. I have some experience with audio electronics, but not quite enough yet to know the details of a turntable signal (what's the impedance?) and how to design the circuit accordingly.

Partly I'm looking for casual advice on the subject, and partly I'm warning that DC coupling, especially for vinyl, is a bad thing. One of the main features of professional audio equipment is good protection circuitry, and this includes AC coupling (for example balanced audio lines). Since we can't really hear below 20 Hz, anything lower than that is electronic noise which is best rejected.

Re:drool...

[the_consumer]

I think you'd have to put the turntable in a seperate room.

Re:drool...

[par38lamp]

Quick thought...

I have a Audiocontrol 2XS crossover in my truck that has infrasonic (below 20Hz) high pass filtering in it. That might be what you are looking for. Possibly pick one up cheap on e-bay. It is 12 volts, though.

I don't know how well it would work with a ceramic cartridge (as opposed to a magnetic with higher output). Turntable=>Phono preamp=> reciever?

Re:drool...

[Golias]

The visible shaking of long-throw subwoofers is a fairly common artifact. It's probably not harming your speaker drivers.

However, if you are worried, I would say you should go to your nearest analog audio boutique for advice. (There's at least one in every metro area... A small audio store which is staffed almost entirely by friendly, low-pressure, well-informed vinyl bigots who only sell speakers which are guaranteed to give any audio fanatic a chubby. They know everything there is to know about the state of the art in all things analog, and usually know more about digital sources than your local Sony dealer. For the Twin Cities, it's Hi-Fi Sounds in downtown Minneapolis. You'll have to ask around to discover the one in your town.)

Re:drool...

[Anonymous Coward]

Don't get hung up on Nyquist. Image a 1Khz sine, to reproduce this with samples you will need well over 2KHz sample rate.

E.g. Image your 1KHz sine being sampled at 2KHz, now think of the sample points, now map them. If you miss the zero cross over points, you get a pulse wave.

Re:drool...

[Golias]

A lot of speaker companies sell test-tone CD's which go well below 20 Hz.

A lot of amplifiers and speakers can't push much out below 20 (which is why output specs are usually evaluated on a basis of how it performs between 20 and 20,000 Hz... 20 Hz is a popular roll-off point, especially with speaker makers), but the problem is not the CD player. Whoever told you that consumer DAC hardware can't go below 20 is simply wrong.

Re:drool...

[FlyingOrca]

I'm with you, except for the Fort Garry. Big Rock rules my world, unless I'm in the UK!

Re:drool...

[mcg1969]

That's why you need just over 2kHz to image a 1kHz wave. Even 2.0001kHz will do, if you use reconstruction filter that's close enough to perfect: you'll get perfect reproduction of the wave.

In practice that's a rather big "if" though. CD players don't use such nearly perfect reconstruction filters; they're too expensive to build. So in a practice, a CD player's useful frequency response end below the Nyquist limit of 22.05kHz, more like 18-20kHz.

Re:drool...

[Anonymous Coward]

No you don't. You need to read up on some basic sampling theory.

Your example is an edge case (you can actually only sample 0.9999999... kHz with a 2kHz sample rate.

However, you do not need "well over" 2kHz to reproduce 1kHz. With a perfect reconstruction filter you can reproduce that sine wave *exactly* if sampled with say 2.1kHz. The only problem is that in the real world there is no such thing as a perfect filter, especially not in the boring analog domain. If you use a much higher sample rate in the D/A converter you can have a much simpler reconstruction filter.

Re:drool...

[Anonymous Coward]

Who keeps modding everything -1 overrated? WHO I ASK! Why Oh Why!

*sobs*

Re:drool...

[dfghjk]

You mean 20KHz Nyquist.

No, no lower limit is necessary for audio CD's. They are often filtered so they don't present an unnecessary load on playback equipment, though. There is no reason that bass can't extend to 10HZ using a CD or DVD, and this is not uncommon on the special effects tracks on DVD's.

Re:drool...

[Anonymous Coward]

"CDs are digital waveforms"
CDs are compact discs, they are not waveforms. Waveforms are not digital, they are continuous. They might represent something that you interpret as something else, but waveforms are all analog. Every last one of them, everywhere, even the clock to your CPU.
"There's no reason they can't produce any freq down to 0.0000000000000001 "

Sure there is, but judging by your post, it's beyond you.

Re:drool...

[proj_2501]

now imagine what it would sound like if you listened to some GOOD drumnbass.

Re:drool...

[Jason R]

One way to AC-couple is to put a capacitor in series . I'm not sure what value you'd need, since you need to take into account the output resistance of the turntable as well as the input resistance of the pre-amp...

Re:drool...

[budgenator]

my amplifier does 10Hz easy, I just twist the volume knob up and down real fast. Seriously, the biggest problem that I see isn't reproducing the sound, it's recording it in the first place, most microphones and pick-ups are magnetic and inductive so they are actualy recording the change in pressure rather than the pressure, the sensitivity of these drop-off as frequency decreases because the wavelengths are so long, there little change acros the device. A capacitative pick-up would help, some kind of laser/doppler pickup would do it also.

I found it amusing the the guys in the article built the sub-woofers in stereo, low frequencies are very non-directional. I'm pretty sure that most elephants have hearing at 10Hz, but I'd guess that their ears are to close together to get any directionality, maybe hump-backed whales would apreciate the system, I know for humans it's over-kill and only good for bragging-rights.

Re:drool...

[DilutedImage]

My CDs must be broken then, because I have never had a problem reproducing sub-sonic frequencies .. .. 2

Re:drool...

[DLWormwood]

You mean 20KHz Nyquist.

No, I meant 20 Hz. That's all that's needed to replicate a 10 Hz signal. Of course, you can't hear anything musical or even vocal with such a low sampling rate, but that's another issue.

A 20 KHz sample rate is usually considered the minimum to enjoy music, but you really need 40 KHz or higher to minimize perceptual distortion. You can get away with as low as 8 KHz for just speech, however. (This is what the old Sun mu-Law format worked at.)

Re:drool...

[gordguide]

Yes, it's very unlikely that an LP record of music will have any information at 10Hz, for a couple of reasons.

Firstly, the resonant frequency of the cartridge will typically be somewhere around 8~15 Hz. Any information on the record that falls in this range will excite this resonance, causing all kinds of problems that basically could be summarized as bad stuff and bad sound. It's filtered out before it gets to the record mostly for this reason.

The actual resonant frequency varies based on the compliance of the cartridge's cantilever (the tiny "arm" the "needle" is attached to) and the tonearm's mass.

You actually want it around 10~12 Hz; below that and you probably will be in the turntable's suspension frequency (again, exiting the reasonance, bad sound and bad things, one common one is skipping when walking around the turntable, etc) while above that and you might have program material (low bass) excite it.

Secondly, low frequency sounds are fairly large when cut on a record, which means the grooves have to be spaced further apart. A music record with a LF cutoff of 20 Hz will be about 16 minutes long; 30 Hz will get one around 18 minutes and if you have any 25 minute records (yes, they made them) chances are it's a rock recording with no bass information below around 40Hz. The cutting engineer selects the cutoff frequency when they make the master, often boosting bass a little higher in frequency to make up for the lost true low info.

The lathe used to make the record master also has some physical limitations that limits exactly how wild you can get with LF volume and frequency.

It's possible to cut a test record of fairly short length with any of these low tones. You need an engineer who really knows his lathe and probably would involve manipulating the speeds of a master tape (if they even used one, it would be easier to feed a test tone right to the cutter) and the lathe.

For example record the tape at 30 inches per second, and for a 45 RPM LP-sized test record play the tape at 10 ips and cut at 15 RPM. (To get a clean 10 Hz on tape, you might have to record at faster than 30 ips, but whatever it takes).

Or send a 5Hz test tone and cut at 1/2 speed. Or some similar combo, whatever the engineer thinks is necessary and within his cutter's physical limits. Played back at 45 RPM you get the desired (correct) frequency. Vary the frequency and get a series of tones running from, say, 5 Hz to 20 Hz in 1 or 2 Hz increments.

Then you would play that record back and see exactly where the turntable's suspension and cartridge resonance frequencies are (knowing that will help fine-tune bass response, suseptibility to footfalls, and a few other things). That's about the only use for such low tones on an LP, and such records are rare.

Re:drool...

[dfghjk]

Maybe not but it's consuming amplifier power.

Generally these things are called rumble filters.

Re:drool...

[dfghjk]

Wow, so you thought important to educate everyone that audio standards have sample rates of at least the required 20Hz. How useful. This makes you seem so intelligent.

Re:drool...

[dfghjk]

It's not the reconstruction filter but rather the antialiasing filter that's the issue. Nyquist says you need 2x the sample frequency, not > 2x.

Re:drool...

[gordguide]

It's the resonant frequency of your cartridge/arm combo. It's dependent on the compliance of the cartridge; ie how stiffly or loosely that tiny arm that is connected to the stylus moves.

Generally speaking, you use a high-compliance cartridge with a light tonearm and a low-compliance with a heavier arm. The idea is to make that resonance around 12 Hz, where there won't be any information on the record or the suspension's own resonance (if there is a suspension) will be lower than that (below 8 Hz). If that works out right, then there's not much to exicte the cartridge/tonarm's reasonance.

You might be able to fix it by switching to a different cartridge; a different tonearm would also help, but is kind of expensive unless you're already at the lunatic fringe and see that as a normal expenditure for audio.

It could also be "rumble" which is mechanical noise from the turntable's motor system. Capstan-driven turntables (basically, a puck) are usually bad for that, belt drive or direct drive should be better in that regard. If you have a record changer (you can stack records on it) or an inexpensive turntable it's probably capstan driven.

Most, if not all amps/recievers with a phono input also have a "rumble" filter; sometimes called things like "subsonic filter" or "low filter". That's supposed to take care of it. Some gear has it built into the RIAA equalization curve, so no switch on the front panel. Engage the filter if you have a button for it somewhere.

Re:drool...

[Anonymous Coward]

It's probably a bug in slashcode. I went to moderate some idiot as overrated in another story, and it gave the guy a fucking UNDERrated. Pissed me off big time.

Those slashdot people couldn't write a "hello world" program correctly if their lives depended on it. Fucking idiots.

Re:drool...

[mcg1969]

No, this is not the case. You cannot guarantee perfect reconstruction of the signal if it has any content at precisely the Nyquist frequency. For example, consider a sine wave at the Nyquist frequency---I can just sample it right at the zero crossings, and there will be no way to properly reconstruct it. So the content in the signal must be strictly below the Nyquist frequency.

Re:drool...

[Anonymous Coward]

Right.

You can record 0.000001 hz (or even dc) onto a CD. Whether you can reproduce that depends on what you play the cd in.

The only Red books specs that actually effect the recording I have seen is that peaks should be max -0.3 db.

Everyone ignores that though, and modern CD players don't have a problem with it.
Really clipped CDs can actually generate peaks above 0db! Seems weird, but after it's been through the reconstruction filter, clipped peaks are somewhat rounded off, which requires >0db headroom for a 'squarewaved' master.

Re:drool...

[dotgain]

I don't remember ever seeing, on the specifications of any CD player, studio/domestic, a frequency response in the order of 0-20,000Hz. Sure, there's no reason a DAC won't go that low, but they'll be fitted with a low-pass filter for sure, as soon as you have 47kohms on the output, 20Hz is probably attenuated to the order of 40dB or so.

Re:drool...

[Bob Davis, Retired]

Most digital audio you'd be getting on CD or DVD is 'mastered' or fixed up in a variety of ways before it hits the stores. This usually involves stripping the lowest bass frequencies out of the mix. On most DVDs I don't think you should be hearing any 10 Hz sounds at all, and if you are they are more likely an artifact of your environment.

Oh man...

[Hugh-know-who]

I can hardly wait for someone to put it in their car, and drive through my neighborhood at 3 am...

Re:Oh man...

[Ziwcam]

Be careful what you wish for... You just might get it.

Re:Oh man...

[Inuchance]

Given the size of this subwoofer, I'd imagine you'd put the car in the subwoofer! (Especially in soviet russia)

Re:Oh man...

[tankdilla]

Forget about waking the neighbors, he'd wake up the Devil or Saddam Hussein with that.

Devil: What the hell is going on up there? Did somebody start the Apocalypse without me?

Re:Oh man...

[Whumpsnatz]

And I can hardly wait to grab the creep and play a tune on his head with a two-by-four. Doesn't anybody recognize that noise is not only irritating, but harmful? Let 'em make all the noise they want, as long as I don't have to feel it. (That's right, FEEL it, not hear it). When speakers shake my car, it's time to perform a little operation on their sound system. With a shotgun.

Re:Oh man...

[Hugh-know-who]

LOL Dude, I sympathize, believe me. But this is slashdot - surely (and don't call me...) we can come up with a more elegant solution than a shotgun. I was thinking more of a car mounted directional harmonic frequency generator which automatically locks onto low frequency vibrations above a certain decibel level, shredding such boom tubes whenever they come within range...

Giant Subwoofer + Barry White Record

[Anonymous Coward]

There in lies the secret to cold fusion

Re:Giant Subwoofer + Barry White Record

[youngerpants]

Its also a way to save the snakes from snake-bashing day

Re:Giant Subwoofer + Barry White Record

[kacp]

Or at the very least, the secret to saving all the snakes in Springfield on Whacking Day.

"O Whacking Day O Whacking Day
Our scared snake-skull cracking day..."

Re:Giant Subwoofer + Barry White Record

[Cleggmeister]

Imagine the sheer number of snakes converging on the town. Let's hope they've not spent too much time planning whacking day...

Re:Giant Subwoofer + Barry White Record

[Paulrothrock]

Baby, I know you been hydrogen waaay too long. You been yearning for a change. Come on over here baby, and fuse with me, make me a whole helluva lot of helium. It's what I need, baby

Que funkalicious bass line...

Re:Giant Subwoofer + Barry White Record

[FFFish]

That's not cold fusion, it's smooooove cool fusion!

Doc brown would be impressed

[plexxer]

*obligitory BTTF reference*

Re:Doc brown would be impressed

[jx100]

might want to turn down the overdrive, though

Dare I ask

[Illserve]

What those apparently puddles of yellowish brown liquid in the pics near the bottom are? Just how powerful is this thing anyway?

Re:Dare I ask

[RetroGeek]

What those apparently puddles of yellowish brown liquid in the pics near the bottom are?

ear wax

Re:Dare I ask

[Diamon]

What's the first thing do you do with a subwolfer that size? Why play the brown noise (that certain frequency that causes someone to lose bowel control and crap their pants) of course.

Re:Dare I ask

[j-turkey]

What's the first thing do you do with a subwolfer that size? Why play the brown noise (that certain frequency that causes someone to lose bowel control and crap their pants) of course.

LOL. That was the first thing I thought when I saw this. Great minds think alike...either that, or like me, you still think that potty humor is funny as hell.

Re:Dare I ask

[Anonymous Coward]

As best I can tell, those are animal hides on the floor. But they DO look like something else, don't they?

If this dude turned up the volume, wouldn't it destroy his house? Talk about raising the roof!!

Re:Dare I ask

[duguk]

The brown note is the note that causes bowels to release.

The brown noise is like pink and white noise; more information here: http://www.techlar.com/fractals/websys.exe/music/b rown.html

The brown note (that causes bowels to release); normally known as the Sphincter Resonance - In the 1960s, apparently, somebody discovered the resonating frequency of the sphincter. They created a device called an "Anal Sphincter Resonator" - an organ-like device. It was used in a suspense thriller play - they intended it to "shake up" the audience when danger was being acted out - apparently it caused the entire audience to soil themselves. It approximately at 5 or 12 hz (I'm unsure which!), hearing the sound isn't important; its a resonance frequency.

I can't find much information from google on it, but you can generate the frequency using a Win32 app called BwGen (Brainwave Generator); the preset is at http://www.bwgen.com/presets/desc475.htm

Dug

Re:Dare I ask

[Diamon]

The brown note is the note that causes bowels to release.

You obviously didn't bother to check out the reference I was using for it.

Cartman: [with recorder] Okay, how about this one, Kenny? [plays an A note]

Kenny: (Uh-uh.)

Cartman: No? How about this? [plays a G note]

Kenny: (Nope.)

Cartman: Hm, interesting. Let's see: how about this? [plays a Gb note. Kyle and Stan turn around on their seat]

Kyle: Cartman, what the hell are you doing?

Cartman: We're trying to find the brown noise--it's this one pitch, this certain frequency that makes people lose bowel control.

Stan: What's "lose bowel control?"

Cartman: That's a scientific term for crapping your pants.

Kyle: Oh, brother, here we go again. Cartman, there is not a sound frequency that makes people crap their pants!

Cartman: Yes there is! The French experimented with it in World War II!

Kyle: Nuh-uh!

Cartman: How about this one, Kenny? [plays an F note]

Kenny: (Nuh-uh.)

Kyle: There is no brown noise, fat boy!

Cartman: That's nice. When I find it I'll just make you crap yourself so you look like Karen Carpenter.

The entire thing regardless of if you call it the brown note or the brown noise is an urban legend. Not turn in your geek button for not picking up on a South Park reference correctly.

Re:Dare I ask

[Walt Dismal]

I experimented with the 'brown note' off hours while working at the Leslie Speakers division of CBS Musical Instruments in the 60s, where I had access to high powered sub base speakers and good amps. You cannot achieve the required acoustic energy levels (acoustic watts, not electrical watts) with home audio speakers. The resonant frequency is between 32 and 37 Hz, and it is real. The thriller play story, as far as I know, is an apocryphal tale, though.

Re:Dare I ask

[Anonymous Coward]

He was just trying to correct you so that you didn't make the same mistake in future? Is South Park more important than the truth/answering a question? Don't answer that...

Old News

[somethinghollow]

This MUST be old news. From the looks of the shwank pad, it must be the 70s. This is where pot will get you. Making giant subwoofers. Oh wait... pot will get you sleeping on the couch or laughing about things that aren't funny.

Nevermind.

Re:Old News

[pahles]

VERY old news indeed. I saw this site for over a year ago...

Re:Old News

[Blastercorps]

It can't be too old, he said he tested it with a CD player.

Re:Old News

[Anonymous Coward]

Oh wait... pot will get you sleeping on the couch or laughing about things that aren't funny.

That's the great thing about this project, you don't need pot to 'get you'. I quote:
"The center seat of the sofa is where real music and emotions live"

So as you can clearly see, the center seat of the sofa was designed specifically for... well, I don't really know where that was going, but their grammer is crap.

Re:Old News

[markfive]

laughing about things that aren't funny.

Sounds like slashdot.

Re:Old News

[Tackhead]

> From the looks of the shwank pad, it must be the 70s. This is where pot will get you. Making giant subwoofers.

That's no subwoofer... it's a bong!

Inspired by Dennis "Marijuana doesn't lead to other drugs, it leads to fuckin' CARPENTRY!" Leary's rant

Re:Old News

[Anonymous Coward]

True - that would be 25 years ago.

Re:Old News

[Anonymous Coward]

Dennis Leary was a hack, and a theif.

Try the real thing somtime. Bill Hicks ladies and Gentlemen, Bill Hicks.

Biggest?

[mal3]

Is this really the biggest? I heard somewhere Larry Ellison had an inground pool in his basement that he had turned into a subwoofer.

Re:Biggest?

[Anonymous Coward]

I heard he had to do the conversion because him and his ego wouldn't fit in the pool anyhow.

Re:Biggest?

[InsaneGeek]

Yea, I'm pretty sure Ellisons old lap pool beats those guys: http://sanfrancisco.bizjournals.com/sanfrancisco/s tories/2003/07/21/focus1.html?t=printable

A candidate for the "bored with extreme wealth" category, though not yet a grandpa, is Oracle CEO Larry Ellison. When he revamped his Pacific Heights home a few years ago and wanted to eliminate a lap pool on the bottom level, Green convinced him to turn it into a massive subwoofer instead.

Green said that when he and Ellison played Jurassic Park to test the system "the part with the dinosaur stomping actually lifted us up out of our seats. (The sound) was moving eight inches of concrete" on the floor.

Re:Biggest?

[djdead]

yeah i was just gonna make the same comment. at 3,000 cubic feet, it's about 85 cubic meters which is almost 42% bigger.

Re:Biggest?

[Animats]

Yeah. Ellison also has a sunlight-visible projection TV in that place. And that's his old house. His new one is the size of a shopping mall, and it's years behind schedule.

See Larry Ellison's Driveway Generator.

In related news...

[ravind]

...scientists are predicting Southern California could be in for a major earthquake this spring or summer.

Disaster Area scheduled to appear

[CarrionBird]

Hotblack quated as saying, "You call that a woofer??"

Re:Disaster Area scheduled to appear

[bettlebrox]

Maybe it's time to get off-planet for this gig!

Disaster Area

Disaster Area, a plutonium rock band from the Gagrakacka Mind Zones, are generally held to be not only the loudest rock band in the Galaxy, but in fact the loudest noise of any kind at all. Regular concert goers judge that the best sound balance is usually to be heard from within large concrete bunkers some thirty-seven miles from the stage, while the musicians themselves play their instruments by remote control from within a heavily insulated spaceship which stays in orbit around the planet - or more frequently around a completely different planet.

Their songs are on the whole very simple and mostly follow the familiar theme of boy-being meets girl-being under a silvery moon which then explodes for no adequately explored reason.

Many worlds have now banned their act altogether, sometimes for artistic reasons, but most commonly because the band's public address system contravenes local strategic arms limitations treaties.

This has not, however, stopped their earnings from pushing back the boundaries of pure hypermathematics, and their chief research accountant has recently been appointed Professor of Neomathematics at the University of Maximegalon, in recognition of both his General and his Special Theories of Disaster Area Tax returns, in which he proves that the whole fabric of the space-time continuum is not merely curved, it is in fact totally bent.

:)

Re:Disaster Area scheduled to appear

[Anonymous Coward]

Depends whether he's still spending time dead for tax purposes.

(Trivia fact - Hotblack Desiato is genuinely the name of a London real estate agency near where DNA lived.)

Re:Disaster Area scheduled to appear

[Analogy Man]

I was surprised to see how far I needed to scroll down the posts before the first HHGuide reference.

When I first saw the concrete work, I thought it was the bunker for the listeners and the woofer would be in a seperate facility.

Re:Disaster Area scheduled to appear

[Anonymous Coward]

DNA apparently almost drove straight off the road when he saw the "For Sale" sign with their name on it. Lucky bastards!

Re:Disaster Area scheduled to appear

[AndroidCat]

For listening to Disaster Area, that's not a woofer, that's an ear-pod.

Obviously they're just...

[clickety6]

...setting up for a "Disaster Area" gig!

Re:Obviously they're just...

[Anonymous Coward]

Yes, there might be trouble with the START treaty.

Not Worth It

[Doesn't_Comment_Code]

I've built my own speakers before, and while you can do a good-enough job without too much hassle, making a first-rate product is very labor and math intensive. If this guy is putting that much money and effort into this project, I really hope he gets all the damping and power equations right. Otherwise this will all just be a publicity stunt (maybe that's what it is anyway). I'm thinking about the amplifier he needs to run it right now. That's a lot of juice! And juice = money. And worste of all, you'd never be able to use the thing! Even a store bought stereo goes well above the municipal noice ordinances. And bass carries the furthest! What is this guy thinking?

If he ever does use it, I bet he'll feel that really cool thumping sensation in his chest though.

Re:Not Worth It

[aderusha]

this might seem odd to you, but some people design listening systems for sound quality, not volume. if you'll RTFA, you find that the amp is only delivering 6W to each of 2 horns (despite total power handling capacity of 6400 watts).

Re:Not Worth It

[julesh]

The setup is designed for high sensitivity, not high power. He's only feeding them with 400W RMS signals, for 6.4 KW total; here in the UK that'd cost about 30p (about 50c) per hour to run. Not a huge problem.

Re:Not Worth It

[Anonymous Coward]

I think they're pros...judging from the rest of the site.

Re:Not Worth It

[AviLazar]

He made it for the same reason why people make things like "the largest pizza" --- because they can! I think it's cool. We need more humor in the media and this brings it. Will he use it at a major event? Maybe he will sell it to a football stadium, maybe it will be shredded - but either way it's just cool. -A

Re:Not Worth It

[karnal]

No. That's what I thought at first as well -- if you keep reading, you'll see that he's only feeding 6w per sub channel (a total of 12w) at the peak of the program.....

So, while a horn costs a lot to build, it doesn't cost much to run....

Re:Not Worth It

[jamonterrell]

What you've failed to mention is that it's also very difficult to find the source of bass in comparison to other frequencies. It's omnidirectional and it will actually carry through the ground better than it will through the air, and if he really cranks on it, it will sound like it is coming from every house in the area, literally. The underground vibrations will carry even better through the concrete than the ground. When that concrete starts vibrating, it's going to cause fluctuation in air contained within the house. Because houses are nearly airtight, the house will then be moving more air with each fluctuation than the open air will be moving on its own. The end result is, if you walk by a nearby house, you'll think it's coming from that house.

Of course this is all spoiled now, because he's given away where he is =)

Re:Not Worth It

[SlayerofGods]

Actually the article also says that the efficiency of the beast is 110 dB/1 watt/1 meter. Now I don't pretend to be an audiophile but from what I generally understand that to mean is that if you put 6 watts in then from a distance of only a meter it would be 660dB more then enough to kill you.... so this thing is indeed loud.

Re:Not Worth It

[Jim Starx]

Not exactly, the equation changes depending on how you have the amp wired. Plus you generally run amps full on and then adjust the volume going into an amp. So even if it's wired for 660dB to be the output that would be the max possible. He can always turn the volume down.

Re:Not Worth It

[HardCase]

Decibels are logarithmic. 6 watts gets you about 117dB. But even 110dB is loud! And the article said that at the couch, 1 watt delivered 100dB. Loud!

Obligatory Spinal Tap reference...

[bennomatic]

The main question is, does it go to eleven?

Re:Obligatory Spinal Tap reference...

[Monsieur Canard]

Can you hear me now? Good!

Umm.. no?

[eddy]

"Someone during concert performaces had clap his hands !!! - to the performers... isn'it a bit strange?"

If so, that's not the only thing that's a bit strange.

Now..

[Anonymous Coward]

Now they just have to make one the size of the city, and they can start crashing smooth black spaceships into a nearby sun for our gratuitous entertainment.

Audiophile

[artlu]

As an audiophile myself, I cannot understand the logic behind this. I have competed in IIASCA sound competitions and had 8 10" JL subs in a custom box to produce nearly the same efficiency of their setup! However, having nearly 6000 Watts is damn impressive, but I can get 3 JL Audio 13-W7's and 3 JL audio 1000x1 and bridge them to 2 ohm for 6000 watts as well!

Re:Audiophile

[valis]

> As an audiophile myself ...
> I have competed in IIASCA sound competitions

You seem to be contradicting yourself.

Re:Audiophile

[Bombcar]

I think the key is the "Total efficiency: more than 110 dB/1 watt/1 meter."

Which I read as 110 dB with 1 watt of power at 1 meter.

And as anyone knows, 110 dBs, even if they're just mysql dBs, is impressive. [/joke]

Re:Audiophile

[Anonymous Coward]

As an audiophile myself, I cannot understand the logic Audiophilia and logic are an oximoron

Re:Audiophile

[Anonymous Coward]

but I can get 3 JL Audio 13-W7's and 3 JL audio 1000x1 and bridge them to 2 ohm for 6000 watts as well!

Uhhh... OK.

*smiling and nodding and backing away from your post*

Re:Audiophile

[karnal]

Quote from the article:

"The real maximum power fed to both subhorn measured with an oscilloscope at the highest musical peak roughly reaches 6 watts per channel."

Now, he's also stating that he calculated for the seating area about 110db/1w/1m. Since my math has gotten quite rusty, I'm assuming with a horn setup that it's quite loud.

What I don't know is if he's doing 6w/ch, meaning 6w to each sub, or 6w to each "set" of subs... so either 12 watts at musical peaks or 96 watts total.... either way, though... watt for watt, this setup would be much more efficient than any setup you could ever place in a car.

Not saying getting loud SPL's out of cars isn't fun, just a different challenge. Usually requires more power, and while you can get a car setup to sound good, working with a true "listening room" (and lotsa cash) can yield almost "perfect" results.

Re:Audiophile

[sweede]

the guy isnt running his setup with 6000 watts, only 6 watts per speaker. With that power he will hit ~115db easy. try doing that with your JL 13-W7's and their high 80's sensitivity.

Although you have to wonder one things.

how did he manage to seal the floor to the top of the horn ?!

Re:Audiophile

[Anonymous Coward]

Are you retarded?

Seriously...you have absolutely no idea what you're talking about.

Re:Audiophile

[man_ls]

db@1w/1m is the efficiency rating...so his speakers are 110db sensitivity.

That's insanely high. (Most subwoofers are high 80s-low 90s, good tweeters are high 90s, max I've seen is 101)

Re:Audiophile

[sogoodsofarsowhat]

First plenty of people have explained here that hes only using 6Watts of power to do this. Your puny JL's will not do this. (These guys are using JBL style drivers...look at the cones you can tell :) ) These are not car type devices which tend to be very low efficiency. These are PRO SOUND drivers (not to be confused with the aftermarket car guys claiming they are PRO Sound. The term refers to Professional Sound Reinforcement ie Concert type speakers. JL does not do this nor does any car sub company.) These drivers are close to 100dB/1w1m sensativitey not 85dB/1w1m. Also they are most likely 16 ohm drivers giving him a 4 ohm load to his amp. Beyond all of these differences the major difference is that he has distortion in the UNMEASUREABLE RANGE.....where as IIASCA pretty much is just measureing distortion. IIASCA may make a lot of money playing to the booming kiddies out there but as far as serious acoustics and sound quality they are a friggin joke. If you cant tell this thing must sound incredible. It has some very serious acoustics behind it and the designer has chosen to not compromise on the setup. I bet it can make your skin crawl :) I have experienced 4 18" Pro subs in a horn loaded design (Klipsch did this a few years ago at CES). It was fantastic. They used 3 watts of power to drive the subs :) Braggin about how many watts you speakers take is sorta like bragging about how much gas you car burns per mile. Less is more....not the other way round.

Re:Audiophile

[Anonymous Coward]

No, he already told us: he's an audiophile. Of course he doesn't have any idea what he's talking about!

I'm off to find some, uh, "Sub Harmonic Cuboid Balancing Stones"[1] to sell to the sucker..

[1]: London red bricks to you and me, but he'll not know the difference!

Re:Audiophile

[MrBlue VT]

He used 20 cm of concrete for the floor that goes over the horns, and 1 ton of marble flooring on top of the access panels. That'll keep things still.

Decible Drag Racing

[mixtape5]

Reminds me of these vans. They made it into a sport called decible drag racing...

http://www.cnn.com/2003/TECH/ptech/07/02/popsci.st ereo.kill/

questions, questions...

[whathappenedtomonday]

everybody's asking "what sense does it make" - i have a different question:

where do i plug in my guit?!

this is awesome. really, incredibly oversized and inappropriate - but absolutely awesome.

Re:questions, questions...

[Anonymous Coward]

where do i plug in my guit?!

I hope that you meant your bass. You know that this is about a subwoofer, right?

Re:questions, questions...

[whathappenedtomonday]

hope that you meant your bass

well, my bass guit is the one with only 4 strings, right?!

Obligatory DNA text

[RexHowland]

The Hitch Hiker's Guide to the Galaxy notes that Disaster Area, a plutonium rock band from the Gagrakacka Mind Zones, are generally held to be not only the loudest rock band in the Galaxy, but in fact the loudest noise of any kind at all. Regular concert goers judge that the best sound balance is usually to be heard from within large concrete bunkers some thirty-seven miles from the stage, whilst the musicians themselves play their instruments by remote control from within a heavily insulated spaceship which stays in orbit around the planet - or more frequently around a completely different planet.

Their songs are on the whole very simple and mostly follow the familiar theme of boy-being meets girl-being beneath a silvery moon, which then explodes for no adequately explored reason.

Many worlds have now banned their act altogether, sometimes for artistic reasons, but most commonly because the band's public address system contravenes local strategic arms limitations treaties.

This has not, however, stopped their earnings from pushing back the boundaries of pure hypermathematics, and their chief research accountant has recently been appointed Professor of Neomathematics at the University of Maximegalon, in recognition of both his General and his Special Theories of Disaster Area Tax Returns, in which he proves that the whole fabric of the space-time continuum is not merely curved, it is in fact totally bent.

Blown Speaker?

[ryanw]

So what happends when this guy blows a subwoofer speaker? He has the speakers under 1 ton of marble if I read it right. That's not a very accessible configuration for maintenence.

Re:Blown Speaker?

[ravind]

The question is, if he blows one, will anyone notice :)

Anyway if you had looked at the pictures, the speakers are easily accessed through a removable floor panel. Similar to the wiring in a server room.

Why is it that people look at a project, which someone else has put a ton of time and effort into, and think they can find flaws in less than a minute. Is your opinion of your fellow man that low, or your opinion of yourself that inflated?

Re:Blown Speaker?

[b1t r0t]

It didn't say the 1 ton was all one piece!

Re:Blown Speaker?

[mrjackson2000]

6w per cone is nothing, they will die of dry rot before they blow out

Re:Blown Speaker?

[mahler3]

Anyway if you had looked at the pictures, the speakers are easily accessed through a removable floor panel.

If nothing else, the output grates certainly don't weigh a ton. Just remove one, and send your buddy crawling down the horn with a flashlight and screwdriver to replace the blown cone. Oh, and promise him that you won't fire the system up while he's down there. ;-)

Re:Blown Speaker?

[duggy_92127]

Why is it that people look at a project, which someone else has put a ton of time and effort into, and think they can find flaws in less than a minute. Is your opinion of your fellow man that low, or your opinion of yourself that inflated?

Finally, somebody says this and gets modded up. I've been posting this for years and always get modded as 'troll'. Sir, I salute you.

Doug

Re:Blown Speaker?

[Politburo]

Why is it that people look at a project, which someone else has put a ton of time and effort into, and think they can find flaws in less than a minute. Is your opinion of your fellow man that low, or your opinion of yourself that inflated?

Because most people find it easier and more self-assuring to point out a minor flaw instead of saying, "Why did I think of that?"

Re:Blown Speaker?

[Anonymous Coward]

"Is your opinion of your fellow man that low, or your opinion of yourself that inflated?"

New around here aren't you ; )
bk425

How about...

[Stavr0]

A giant subwoofer made with a wooden speaker cone soaked in sake?

From the article...

[Junior J. Junior III]

Walls and ceiling seems to fall down, but don't.

Wow, they must have a killer psychedelic budget in addition to the insane audio budget.

Mod me down if you must

[Kulaid982]

All your BASS are belong to us

Re:Mod me down if you must

[ultrasound]

Is that a geek fishing joke? Maybe they would appreciate it here?

shame video didn't get the same attention

[dfghjk]

Too many non-neutral colors for critical viewing. This is also impressive for people who believe tubes are the only way to go, yet tubes aren't known for neutral rendering or good bass response and horns aren't known for smooth response either. I'd say this may be the largest and most efficient home subwoofer (who knows) of its capability but I doubt it's the best. I use 12 18" BagEnd subs in a concrete chamber beneath my home theater. That a 3KW amp does the trick nicely and extends every bit as low as this job.

Re:shame video didn't get the same attention

[Chairboy]

Make sure you run only quality Monster brand optical digital cables. I have it on good authority from the guy at Circuit City that if you aren't using Monster, the actual bits for the data stream have little jags on them that true audiophiles can hear.

Re:shame video didn't get the same attention

[Anonymous Coward]

Nah, monster cables are too cheap. You want the ones that cost $5,000 per foot. That smooth sound you hear is your wallet melting...

Re:shame video didn't get the same attention

[steevo.com]

Make sure your Monster Optical cables are gold plated, of course.

Re:shame video didn't get the same attention

[jimsum]

Have you actually listened rather than just make fun? I didn't think cables made any difference, but I sat down and listened in an audiophile store and decided that it was worth paying $350 for a 3 foot digital cable.

I have compared CDs burned in the "music master mode" on a Yamaha CD burner to the CDs burnt in a normal player. Both my wife and I could identify which disk was which 100% of the time, even using a friend's non-audiophile system. Explain to me how two CDs that contain identical digital information can sound different.

As far as the "little jags" on the data stream, that sounds like an attempt to explain jitter. Using digital means the right data will be transferred through the wire, but jitter means there will be variation in the timing between samples. Because digital players extract clock timing from the input signal, variations in jitter in the wire might affect the output waveform.

I get as big a laugh as you do out of the ridiculous claims for why some things improve the sound. But, just because someone can't explain why something works doesn't mean it doesn't work; and just because you can't measure a difference, doesn't mean there is no difference.

Re:shame video didn't get the same attention

[jimsum]

Why do you think $5000/ft cables are not worth buying? There are probably audio devices that will give you more bang for the buck; but believe me, audiophiles would be very happy to spend less. Many of them are even satisfied with Monster Cable.

Expensive speaker cables are not like expensive cars. You can impress most people with expensive cars; but people just think you're an idiot to buy expensive cables, as I know from direct experience :-). Question the sanity of the 50 year old guy in a Porsche hoping to pick up chicks; you can be sure that someone who buys $5000/ft cables got them because they improve the sound.

Re:shame video didn't get the same attention

[Prune]

the actual bits for the data stream have little jags on them

Sounds like you mean jitter, except it has nothing to do with the bits themselves, but the timing. If you don't think it's a real issue, go read some engineering application notes and DAC datasheets at Analog Devices or Cirrus to be proven wrong.

As for the way you phrased that, either the Circuit City guy was an idiot and explained it poorly, or you are an idiot and didn't understand him well.

Digital cables can have some effect on jitter, and thus affect sound. However, this effect is small, so the only thing that really matters for the cable is impedance matching, as the S/PDIF standard specifies 75 ohm cable. Any 75 ohm coax cable, like the one for cable TV, is good enough, and better than the usual RCA analog cables people use. Also, jitter is significantly reduced in modern recieving equipment that does asynchronous sample rate conversion, because the datastream is reclocked to a local low jitter oscillator (although incoming jitter still does have some impact).

Re:shame video didn't get the same attention

[Prune]

just because you can't measure a difference, doesn't mean there is no difference Huh? You can easily measure jitter, so I don't know why you felt the need to say something like that. If you can't measure a difference, often it means that you can also not hear a difference, once psychological bias is removed in a properly implemented double blind test.

Re:shame video didn't get the same attention

[dfghjk]

Prior to jitter being identified as an issue of there was no means to measure it. At that time, the inability to measure it meant it couldn't possibly be heard (according to some). Hearing, verifying and measuring are at times difficult to do but important nonetheless. I don't expect readers here to be open minded about it in any event.

Re:shame video didn't get the same attention

[Anonymous Coward]

I'd question the guy who spends $5000 on cables instead of buying $5000 worth of concert tickets.

Re:shame video didn't get the same attention

[Chairboy]

Holy crap, you take that stuff seriously? Jitter is induced by signal interruptions in the PCM data stream.

There was no Circuit City salesman, just a very sad you. Try the pepsi challenge someday with a $350 digital cable compared to a $10 one. It either works, or it don't.

If you are suggesting that the only alternative is that the salesman may have rigged the demonstration because he detected a sucker, then I, for one, am shocked.

$350 for a 3 foot DIGITAL cable? BWAHAHAHAHAHA!

Re:shame video didn't get the same attention

[Anonymous Coward]

I *HOPE* you are kidding. They, and I am not kidding here, made that cable for under 5 bucks.

More than likely the dude rigged the thing. You got RIPPED off. Dont belive me? Go buy a 10 dollar cable and plug it in to the SAME spot. I would be willing to BET you could not tell the difference. Dont belive me? Get someone else to plug the cable in but do not tell you which one is which. Do it 10 times, 5 each way. Have your friend mark which way you THOUGHT it was. Bet you end up wrong ~50% of the time.

Lets say I am watching a DVD. For example MOST of the distortion in my system comes from my AMP. Its an 'ok' on not the best but ok for what I do. Some comes from the dvd player itself. VERY VERY VERY little comes from the cables. Also a bit comes from the speakers themselves. Best place to eliminate noise is to invest in better equipment. Just keep an eye on THD. The lower the better.

Is there a difference between digital and analog. YOU BET. Digital to most people sounds much cleaner. But to some people it doesnt sound as 'warm'. I like clean. You probably would have been better off with a 20$ optical cable. I personaly can not tell the difference between a pcm cable (which is just an RCA cable) and a optical pcm cable. It is DIGITAL data. There is no 'distortion'. That is the whole POINT of digital data. Does the actual wave form thats forming the 'digital' have 'jaggies' probably. But it does not matter because it is either 1 or 0, not sorta 1 or sorta 0. The decoder ignors it. If you have REALLY crummy cables (like what comes in a ps2) you might notice it get a 0 instead of a 1 but I doubt it. On my stereo (-55 to +20) I have to turn it up to like 5 before I can hear the distortion (and that IS out of the amp). My neighbors a couple of houses down would probably call the cops if I left it there ;)

Also as for your 'burned' CD. Whatever your using to 'burn' the CD is probably down converting it to a different format then converting back to red book. Rip it as an ISO and reburn. I would be willing to bet you couldn't tell. Also MANY CD's these days are actually produced to be 'louder'. What that means is they pump up the volume a bit for you. Well this tends to clip out when you down convert. It makes the song sound 'muddier'. They do it so when a DJ gets it on a radio station it will be a 'tad' louder than the last song. In theory you get noticed more. In reality its just anoying.

Do not get mad at me. Get mad at whoever talked you into a 350$ cable. My friend who is also REALY into this uses welding wire. But he is also dragging some real power across those lines. Also welding wire was probably overkill. But it was what he had on hand. Thats not specialy shielded or anything. But his system sounds awsome. It should too since he measures every input and output. He is SUPPPPPER picky about it. Its a bit funky in the mids (he likes bass). But that is due to the way he built his box not the wires amp or anything.

Re:shame video didn't get the same attention

[jimsum]

What I meant to say is we can't directly measure sound quality. We can measure many different things, many of which have been found to affect sound quality; but there is no set of measurements (yet?) that will always tell you which device sounds better.

Jitter is a good case in point. I disagree that you can easily measure jitter; special devices had to be built because jitter in a good CD player is measured in picoseconds. I think everyone assumed that picosecond-level jitter was inaudible, and if you calculate the distortion caused by jitter that low, it was a reasonable assumption. There is also the problem that CD players with lower jitter do not always sound better than CD players with higher jitter. So while you can measure a difference in jitter, that difference alone is not going to tell you whether a CD player will sound good; and that is true of all audio measurements.

Re:shame video didn't get the same attention

[jimsum]

First I'll say the obvious, the "digital" cable is not passing a digital on/off signal, it is sending an analogue waveform which is decoded into a digital signal. The decoder tolerates a certain amount of analogue distortion; so I agree with you, the $10 cable is good enough that the correct digital values are sent through the wire.

The problem is that we don't listen directly to the digital data; we listen to a reconstructed analogue signal that requires the correct value at the correct time. If the digital samples are not played back at a steady rate of 44.1 kHz, there will be distortion; the values might be right, but if the timing is wrong, so is the output signal.

The timing issue is relevant to "digital" cables because the analogue signal in that cable is used for two purposes, sending the data and sending a clock for timing purposes. The CD protocol is very robust for sending the data, but the timing information can be significantly affected by bandwidth and other characteristics of the cable used.

Whether the correct data values are transmitted through the wire is only one measure of whether a cable is good, and two wires that transfer the same data values are not the same if they transfer different timing information.

Now, I don't claim that timing differences (jitter) are the reason that cables sound different, I was just trying to show that "It either works or it doesn't" is not necessarily true. There is no reason to think a more expensive cable is better than a cheaper one, but there are reasons to think that different cables are worth listening to.

I did try the "Pepsi challenge" between cables when I bought my digital processor. I took my own CD player in, picked my own CDs, and brought my wife along for a second opinion. We told the salesman when to change the cable or CD and spent at least an hour listening to the different cables. Before I started, I didn't think there would be any differences between cables, just like you. I'd rather have spent $350 on more CDs than on a cable, especially since it makes people think I am an idiot :-), but the difference I heard was worth paying for.

By the way, if you need more evidence that I am a flake, I can hear differences between CDs too! I bought a Yamaha CD burner that has a special audio burning mode. This special mode lengthens the "pits" on the CD so that you get less total capacity, but more accurate burning of the data. The special CDs sound better, and in a blind test performed by a friend on his CD player, my wife and I had no problem identifying which was recorded using the special mode. Note that the digital values on the normal disk are exactly the same as the special disk; yet for some reason, my wife and I can hear a difference.

Re:shame video didn't get the same attention

[jimsum]

I am not kidding, I heard differences between digital cables, and I was surprised. I didn't want to believe it because I'd much rather spend $350 on CDs than on a cable. I did everything I could to test the cables; this was not a rigged demonstration. I took my own CD transport and digital processor into the store, and used CDs I brought. I spent more than an hour comparing cables, and my wife listened too; we both agreed the cable was worth the cost.

As I explained in a different lengthy post, there is more to converting a digital signal to analogue than just the data values themselves. A digital decoder has to output the right value and also output it at the right time; incorrect timing causes distortion, just like incorrect data. Both digital values and timing information are transmitted through the wire; the data values are digitally encoded and so are not much affected by the wire, but the extracted timing information is analogue (i.e. the timing is derived from when the samples arrive), and therefore more sensitive to the cable than the data values.

You may be right that optical cable is better, but my CD transport only has an RCA connector. I have also read that the typical plastic fibre optic cable has less bandwidth than an RCA cable, and since the bandwidth affects the timing information, I believe the reviewers that said RCA can be better than optical.

I will agree that the differences between digital cables are subtle; the people who designed the interface did know what they were doing. Maybe the digital cable was just compensating for flaws in the design of my components, and different components would sound fine with $10 cables.

The difference between burned CDs was less subtle. Here's the link that convinced me to buy a special CD burner:

http://www.yamaha.ca/computer/cp_AudioMQR.asp

I did a blind test on the burned CDs to find out if I'd been ripped off. I had a friend switch disks while my wife and I listened. We both heard the difference between disks burned conventionally and those with the special Yamaha mode. We couldn't really tell the difference between the original and the special Yamaha disk (or say which was better), but the normally-burned disk was obviously worse than the others.

Also try . . .

[Prince Vegeta SSJ4]

DJ Majic Mike

We used to have fun with this one in college, so much bass - would make my eyelashes vibrate

Re:Also try . . .

[budgenator]

we used to use the drum solo in Iron Butterfly's "In A Gadda Da Vida" to blow out candles

Officer?

[Himring]

Speaker guy: Is there a problem officer?

Policeman: The neighbors are throwing up. Can you please turn down your gigantic, crater-filling sub-woofer?

Speaker guy: Huh?

Resturant at the end of the Universe

[aaron_pet]

I seem to remember a scene in one of the Hitchikers Guide series in which a planet was sacrificed for the sake of driving a gargantuan set of speakers.

I pitty his neighbors

I'm not saying it's real, I'm not saying it isn't.

[Anonymous Coward]

But when I hook this up to my recorder and play the 82 Cents Above the lowest E flat Stan and Kyle will rue the day they called me fat. I'm big boned God Dammit!

For a direct-radiating subwoofer, check this out

[mhesseltine]

Richard Clark's "Bread Truck" subwoofer

Here's a guy who designed and built a custom driver to compete in car stereo SPL competitions. The driver was built to be mounted in the box of an old bread truck. It was driven by 2 custom 10,000 watt amplifiers.

Unfortunately, one giant sub doesn't always work as well as several smaller ones, because he didn't win squat with this setup. However, it's not like he needed to prove anything to those in the car stereo world (check out some of the tech briefs on their Main Autosound2000 website)

Obligatory Weird Al Reference...

[Vexler]

Frank's Two Thousand-Inch TV.

bigger isn't always better

[NeedleSurfer]

indeed, the response time of this woofer must be extremely slow negating any good effect it might produce on the frequency range. First you will need a very powerfull amp to drive it so that you actually hear something and even then all sounds will be muffled, bass and bass drums and explosions won't have any attack because even with the appropriate energy the size and weight of the cone will prevent any sudden movement of the cone. In effect the cone will react slower than the sound going in, providing natural compression.

It will just sound like an aural pool of mud. Subwoofer often need a lot more energy to drive than a tweeter, this is why on bi-amplified or tri-amplified system you will read that 250watt goes to the bass, and 70 watts to the tweeter, imagine what's needed to drive this correctly. Not to mention that at this size it nearly impossible for the cone to be even and solid (if part of the cone are moving before the rest it will just sound, well, disgusting).

Impressive to look at, disgusting to hear, funny to read!

Re:bigger isn't always better

[Anonymous Coward]

Did you read the article, or even look at the pictures? They aren't using one big woofer. It's sixteen smaller ones in a specially-shaped chamber.

Re:bigger isn't always better

[Aniquel]

RTFA. It's a horn subwoofer, not a cone. Compression is achieved using 8 10" woofers - not one big one. I do agree with you though - I can't imagine how this could sound good.

Re:bigger isn't always better

[djh101010]

It will just sound like an aural pool of mud.

Seems that you didn't RTFA. This was built by a company who does sound engineering, and is their own showcase system. For some reason, I think that they probably have a better handle on what will sound good or not than you could get from looking at some pictures of their design.

Further, the "attack" you mention that it won't produce for bass drums and explosions, are high-frequency components of those sounds, which are handled by the other speakers. TFA doesn't say this is the only speaker in the system, and TFPictures show what else is in use. The highs get handled by those, the lows get handled by this.

Re:bigger isn't always better

[nattt]

It's a horn. A horn is an acoustic transformer, which matches the impedence of the cone to the impedence of the air, giving a very effecient energy transfer. That means very, very fast bass, with more attack than any brute force method you describe. Your speakers are the equivalent of hitting a feather (the light air) with a golf club (heavy cone). The feather won't go far as there's a big impedence mis-match. The horn gradually makes the air the cone is trying to move match with the weight of the cone, so to speak, like replacing the feather with a golf ball in the above analogy. When the cone moves the air now, it moves easily because of the matched impedence.

To give you an example, my small horn speakers with a 7.5 watt amp go as loud as my brother's PA speakers on his 750watt amp. Do the logarithms and that means that my speakers are 20db more sensitive than his - because of the horns! (actually about 6db of that is due to bigger magnets, but the rest of the increase is down to the horns)

So, the end result is many, many times superiour, with louder sound, with less distortion than your "box" speakers.

Re:bigger isn't always better

[jimlintott]

It's horn loaded. Ever heard a trumpet or a tuba?

Re:bigger isn't always better

[Anonymous Coward]

Not only did you not RTFA. But you didn't even look at the pictures to see that it isn't a single large cone. I can't blame you too much. Apparently the mods didn't look at the pictures either.

Re:bigger isn't always better

[NeedleSurfer]

I'm sorry to contradict you but the attack of a sound has nothing to do with frequency, at all.

Any sound has an amplitude envelloppe which describe the evolution of its amplitude. The attack, wich is the time required for the sound to go from 0dB to its peak level, its hold time, which describe the time it will remain at that peak level, the decay which describe the time it takes to go from its peak level to 0dB. Obviously nothing is that simple and usually a sound has a very complicated envelloppe, a violin sound will decay to another hold time before going to its last decay for example, a complex explosion will have a lot of decays and holds, even several attacks if several burst are heard.

Frequency has nothing to do with the amplitude envelloppe, nothing. The only reason I could see someone making that mistake is because he used a software like Maxxbass which trick the listener in believing there are more bass in the program by adding the artifacts and higher harmonics generaly associated with a complex bass sounds to give the illusion there is more bass and a better attack but that is a psychoacoustical trick not reality, a pure bass sound (sine wave) will still have an attack, a hold and a decay, a good monitoring system will actually make Maxxbass sound bad since the system actually reproduce the bass Maxxbass is trying to simulate. Your brain usually reconstruct the bass signal by himself according to those harmonics and artifacts without you actually hearing them in a cheap system, like a ghetto blaster for example, the brain is a powerfull masking tool.

Re:bigger isn't always better

[dfghjk]

Horn don't result in "faster bass". That's an absurd concept, as frequencies only "travel" as fast as they need to. Transients include high frequency components that aren't handled by the subwoofer. The original poster didn't know what he was talking about but you didn't do any better.

Horns do indeed provide great efficiency benefits as well as vastly improved harmonic distortion, but overall they do not exhibit less distortion that "box" speakers. Horns have terrible directivity issues and have very poor frequency response. In this much more important measure of distortion horns don't measure up. For high volume applications horns are desirable and are commonly used, but for near field listening they blow.

Re:bigger isn't always better

[djh101010]

I'm sorry to contradict you but the attack of a sound has nothing to do with frequency, at all.

Likewise, I am loath to contradict you, but I believe you don't quite have it right either.

Sound, as reproduced by speakers in this example, can be described as a combination of amplitudes of varying frequencies. If you put the sound through a Fast Fourier Transform, you can visually see the different frequencies which make up what you think of as the sound. A 20 Hz sound is going to have a slope which is, by definition, constrained by the shape of a 20-Hz sine wave. If the attack of the sound is faster than the slope of that line, that difference is made up by another sine wave (or waves) of higher frequencies, the sum of which add up to the resultant sine wave. A FFT ('an fft?') will show the components of the sound graphically, here is one example. If you took an FFT of, say, a cannon blast, you'd see the low frequency component you expect, but the initial attack would show up as a higher frequency component which is, in this case, handled by the non-subwoofer speakers.

In other words, to get the A of the ADSR to the slope necessary, higher frequencies have to be added to the low frequency to get there. A fast attack, by definition, has to come from higher frequency sounds; it's the only way to get the sum from one place to another quickly.

Re:bigger isn't always better

[Anonymous Coward]

Electrostats and magnetic planar speakers couple to the air with thin membranes.

Much better than cones.

Re:bigger isn't always better

[NeedleSurfer]

wrong, use a sine wave of 50Hz with a very fast attack (say 10 ms) and all the frequency contained in the resulting sound will be 50Hz, period, no harmonics nothing but 50Hz, fast fourier or not. A canon sound isn't a bass frequency program allone, several very high frequencies will be emited, some as harmonics, some as fondamentals. The fact that you see those high pitched frequencies has nothing to do with the attack of the sound.

If you want to verify this, it's simple, again, use a sine wave of 50Hz, give it a very fast attack and all you will see will be 50Hz. Of course I hope your speaker can reproduce them, if not use 250Hz if you which, it doesn't mater, if you generate 250Hz as a sine wave (no harmonics) with a very fast attack all you will see is 250Hz.

And btw, some people here are right, I just looked at the page and back when I saw the first picture, I was on the impression it was a single cone setup. I backed here and wrote, I was wrong, its a multiple cone setup, my bad. If it would have been a single cone setup if would have been like I said in my first post, very bad. However, concerning the attack of a sound you are plain wrong, the attack is an amplitude property, not a frequency one.

Re:bigger isn't always better

[Prune]

Plasma tweeters are even better -- ionized air couples to air, no solid vibrator.

Unfortunately the RF, ozone and oxides of nitrogen generated make it not too practical, and there is right now only one commercial manufacturer left, Acapella.

Here are some plasma tweeter pictures: http://www.plasmatweeter.de/acapella.htm

A number of people have built their own designs.

Re:bigger isn't always better

[Prune]

Bullshit, attack is irrelevant. From Nyquist's theorem (not theory, theorem, which means it's proven) we know only two samples are needed to reproduce a wave. Two samples do not give sufficient information to specify some special shape for a waveform. Since human hearing is self low pass filtered at 20kHz, as long as the equipment can slew the output fast enough for a full volume 20kHz sine, it's sufficient (assuming the input signal has been bandwidth limited to 20kHz, otherwise you get transient intermodulation when higher frequencies that you can't normally hear exceed the equipment's slew capability).

Re:bigger isn't always better

[gordguide]

Horns will typically exhibit different distortion characteristics than, say, cone speakers. The high efficiency, for example, means the amplifier will be operating at a different part of it's range and can (but not always will) have much lower distortion at that level. Taken as a whole, they can sound terrible or quite good in comparison to conventional speakers.

They do work very well over a limited frequency range, however, and a sub qualifies there. Especially if it's a true subsonic frequency that is felt more than heard; the "seat of the pants" is far less annoyed at harmonic distortion than the ears are.

I don't see many problems with properly designed horns at subsonic frequencies, given enough physical space to pull it off, especially compared to the typical distortion characteristics of larger cone speakers which generally run around 10% THD at very low frequencies.

Since we easily tolerate large amounts of 2nd harmonic distortion (in fact, we don't even recognize it as distortion at all unless we are very familiar with what the original instrument sounds like unamplified) but are very sensitive to 3rd and other higher harmonics, sometimes the "total harmionic distortion" figure doesn't correlate to what we consider pleasing sound, so it's clearly not impossible to build a good sounding sub with cone speakers.

You are right that there are far more examples of poor sounding horns than good ones, but properly designed they can be quite amazing and lifelike.

They generally do have a character that is quite different from cone speakers and not everyone likes it, but then again you can say that for electrostatics and planar systems as well.

Computers, and CNC manufacturing, ironically, help enormously with the very complex math required to build a good horn, which for most of hifi's history were poorly designed and it shows.

Like you, however, I prefer conventional speakers overall; but I've certainly heard some very good horn speakers that have some qualities I can't get with cone speakers. The last word on any of this technology hasn't been written yet, there's room for improvement on all these topologies.

Re:bigger isn't always better

[wabbit3.0]

The comment by dfghjk is right on the mark. Most listening occurs in the near field. At base frequencies you need to be in a very large space to get into the far field of any acoustice radiator. I always had to laugh at the rich kids who had Klipsch horns in their dorm rooms.

Re:bigger isn't always better

[NeedleSurfer]

look you obviously have no idea what you are talking about, you went from telling be that different speakers were producing the frequencies needed to make the attack of the sound, to using a canon sound sample as the basis of an spectrum analisys and tell me that since high frequencies were in the sample it was proving that high frequencies produce the attack of the sound, I told you what was happening I gave you a test to do to prove my point. You come back with the Nyquist theorem, which is a theory that concerns analog to digital audio conversion, you look... confused. Look, I've studied in audio and I work in audio since then. I've built studios, all kinds, from school labs and post suites to project studios, I worked in post-prod and I've been doing live sound for the past 3 years. I know my trade, whatever the mod points distribution says.

I'll repeat, the only mistake I made was to believe it was a single cone setup, because I just peeked at the page and drew conclusions, I was wrong, its a multiple cone setup and that changes a lot of thing, actually it might even sound pretty good, now that I RFTA, but what you are telling me is just very confused and doesn't make sense and doesn't even relate.

You mean...

[sxltrex]

...like this?

Re:You mean...

[Hugh-know-who]

OMG, I knew it!

Re:You mean...

[Anonymous Coward]

I could think of a few ways to make that cost 1/10 as much, if they don't care about sound quality. What a waste of money.

Re:You mean...

[aynrandfan]

Or like this?

Actually, this is an old pic of a legendary sound-off vehicle. Current sound-off cars are crazy like that almost as a norm :)

It's amazing how much you can geek out your car's sound system these days.

I'm not an expert...

[julesh]

... in amplifier design, but something they've done confuses me. It seems they've replaced the negative feedback amplifiers that are normally found in hi-fi equipment with amplifiers that use no feedback at all.

My understanding is that negative feedback improves the temperature stability and frequency response of an amplifier for virtually no cost. Why remove it?

Re:I'm not an expert...

[26199]

Because it's the same word as the feedback you get when you put a microphone too close to the speakers?

Who knows. Odds are the electronics cost far more than they should have done, but audio electronics tend to, I think :-)

Re:I'm not an expert...

[Laser_47]

Negative feedback is used in transistor amplifiers to eliminate even harmonics (2X 4X 6X) that your ear hears as distortion. The downside is that it also eliminates odd harmonics (1X 3X 5X) that pianos and acoustic guitars produce naturally. Tube amplifiers don't generate the even harmonics, so they have no need for the negative feedback.

The early 70's Marketing pushed the THD (Total Harmonic Distortion) measurment as a indication of superior design of the trasistor amplifiers. A good tube amp may have as much as 5% THD compared to a 0.001% transistor amp, but any true audiophile would rather the tube.

Of course, if all you listen to is rock, the distortion is already in the recording, and you probably won't be able to tell the difference other than the transistor will be able to produce more Watts/$. I had to have this pointed out to me while working at a Hi-Fi shop (all I listened to was rock at the time)

Re:I'm not an expert...

[b1t r0t]

Why use oxygen-free speaker wire? For the same reason. People with too much money and too little understanding of how the human ear works (or doesn't).

Re:I'm not an expert...

[dfghjk]

Well, if they're using horns I doubt they're too concerned with frequency response.

Re:I'm not an expert...

[dfghjk]

I wouldn't say that any true audiophile would rather have the tube. I've heard a one or two good tube amps in my day along with a few bad ones, but nothing touches my Levinsons. I'm certain there is other good equipment but I'm also certain that solid state is competitive with tubes.

It also doesn't matter what you listen to. Absolute fidelity should be the goal every step of the way and my experience is that "audiophile" equipment frequently fails to measure up to that ideal. This is especially true of equipment that needs certain musical forms to "appreciate" it.

Re:I'm not an expert...

[dfghjk]

Speaker wire can make a difference in the sound of a system but it is dependent on the speakers and amplifiers as well as the wire itself.

People who deny this have never attempted to evaluate it for themselves and are probably in no position to anyway. Instead, they ridicule those that believe differently and suggest there is no technical basis for the claims. Of course, there certainly are technical reasons wire speaker cables can make a difference, but that's another matter.

Re:I'm not an expert...

[GoneGaryT]

My understanding is that negative feedback improves the temperature stability and frequency response of an amplifier for virtually no cost. Why remove it?

Purity. Negative feedback is never quite phase coherent with initial signal, you get filtering effects and so on. AFAIR, Bob Carver's wonderful Phase Linear power ampflifiers ran on a similar principal - they sounded terrific, which is why Pink FLoyd's techs chose them as PA power for the Wall tour 25 years ago. We did an A-B test blindfold between these and some MOSFET power amps years ago - and could tell the difference in a matter of seconds. The Phasies won hands down, of course.

Re:I'm not an expert...

[Anonymous Coward]

WARNING - AUDIOBULLSHIT ABOVE.

If you want your output to look like your input but with more aplitude only, the only stat that matters - the ONLY stat that matters if THD.

If you want the highs to sound softer and the cajoobyjoob to be joinkajinked, you could just kill youself now, and save the money, because you are a waste of flesh.

Re:I'm not an expert...

[Anonymous Coward]

WARNING - AUDIOBULLSHIT ABOVE.

Wire is wire, as long as it's thick enough.

Re:I'm not an expert...

[dfghjk]

So how much is thick enough? How long is too long? What's the output impedance of the amp and what does the load of the loudspeaker look like? How much linear inductance and capacitance is acceptable?

Trouble is that you don't know nearly enough. Anyone with experience using tube amplifiers will tell you speaker cables can make a huge difference. I'm not a tube lover, but speaker cables make a big difference in my system. Sorry you haven't had the pleasure of experience how obvious this is for yourself.

lovely

[Anonymous Coward]

I must assume these guys lived in the dorm room next to me at college. Specifically, behind the wall that my bed was against.

Meanwhile in the afterlife...

[Trikenstein]

the standing waveform that was once Nikola Tesla makes the harmonic that now passes as its smile.

OK for the kids' room, but what about the theater?

[swschrad]

notice that this was all powered by single-ended triode tube amps, and they rejiggered the output of a marantz CD player for essentially SE triode amps (for that is what you get out of a junction FET.) they used 300Bs in the back channels.

dudes are somewhat obsessive with their victolas,wot?

that should be a reference room to judge other stuff by.

oh, it used to be ultra-common to build echo rooms in sound studios for enhancement of dead-miked voices. while it is not so common now, that's how you avoid creating artifacts and bogosities, big quantities of very dense building material. hope they used acoustic concrete, with extra deadening fibers. otherwise, I'd hate to have to fix the buzz in the bass if a chunk of concrete fell of the brick wall and left a crack.

Re:Giant American Evil!

[jamshid42]

d00d, we gotta get film footage to create proper textures for Doom3 somewhere....

Hotblack

[thorgil]

I've heard Hotblack Desiato used a black hole as a subwoofer at the galaxy twist gig next saturday.

Fans whom have will heard it claims:

-It really rocked!

Oh Joy!

[Virtex]

The neighbors must be thrilled!

Bowel movement

[erbert]

I was in a recording studio a while back and the sound engineer was explaining to me that sound at a certain lower frequency (I don't remeber the exact frequency) causes almost immediate bowel movement. Perhaps this sub-woofer could come in handy at retirement communities

Re:Bowel movement

[ultrasound]

The frequency is known as the brown noise .

No shit!

Re:Bowel movement

[stoofa]

This concept has been bandied about for use as a 'sonic weapon.' Here and here have some details.

The bowel movement is not the main 'thrust' of the argument for weaponry use however as a high percentage of soldiers soil themselves in combat anyway.

Christian Cook
thinctanc.co.uk

Re:Bowel movement

[dotgain]

ultrasound(472511) - he he he
"...known as the brown noise" - har haaa haaa
No Shit! - Oh ho hoo, stop it you devil, you!

Broken english, but...

[The Famous Brett Wat]

Walls and ceiling seems to fall down, but don't. The sound pressure is concentrated at the listening point and stopped by a 2 meters high woolglass anechoic wall on the back of the listening position.

Would you dare sit at this listening point? Is this where the Spanish Inquisition positions the comfy chair?

Re:Broken english, but...

[Anonymous Coward]

I wasn't expecting the Spanish Inquisition...

Re:Broken english, but...

[identity0]

No one expects the Subwoofer Inquisition!

Wooden speaker cones

[raider_red]

Now they just need to get these guys together with the guy from the previous article on wooden speaker cones. Together they could buile the ultimate audio system. How much sake were they drinking when they came up with this idea?

Does it cause involuntary bowel movement ...

[Anonymous Coward]

... for everyone living within a radius of 100 square metres?

Big subwoofer designs

[JBMcB]

A guy I work with used to design loudspeakers. He said the editor of one of the car audio magazines had a custom subwoofer system built into his house. There were two towers with 6 12" subwoofers each, a hole driven into the bottom of each tower and ported into the basement (Infinite baffle design) Add a few thousand watts of amplification on a dedicated circuit and you have a system that will shatter glass.

Suspended me in that room.....

[thejuggler]

I wanna lay suspended about 5 feet off the floor while the BASS is at FULL volume, no treble, no midrange, just BASS. I don't wanna hear a thing, just feel it baby.

> more bass

Re:Suspended me in that room.....

[GWTPict]

I really doubt you'll find tone controls on their amplification.

Wow, flashback to high school (Other bass CDs)

[mhesseltine]

• Bass Mekanik
• 95 South AKA Quad City DJ's
• Bass Patrol
• Techmaster P.E.B.

This text is filler, because apparently my per line character rating is too low. Hopefully it's an average, so this fluff will bring it up. Please fix Slashcode so that this crap isn't a problem. I have sincere doubts that it does any good to stop the trolls (browse at -1 if you don't believe me). So why torture your other readers/posters by making them jump through the troll hoops?

Re:Wow, flashback to high school (Other bass CDs)

[silkySlim]

What about DJ Magic Mike? ;o)

Re:Wow, flashback to high school (Other bass CDs)

[mhesseltine]

See parent to my post. He was already mentioned.

Re:Wow, flashback to high school (Other bass CDs)

[_Shorty-dammit]

there's a fair bit of "music" these days that has a lot more bass content than those old bass CDs, rather than a "bass CD" just to have bass. There was that "oooh" factor back when those discs first came out, but they're anything but listenable music. Check out something like The Crystal Method's Tweekend album if you want something that's listenable and has enough bass to show off any system, more than a lot of those bass CDs at that. There's tons of other stuff out there too, lots of good music with tons of bass, and those old "bass CDs" should be buried forever :)

Re:Wow, flashback to high school (Other bass CDs)

[mhesseltine]

there's a fair bit of "music" these days that has a lot more bass content than those old bass CDs, rather than a "bass CD" just to have bass. There was that "oooh" factor back when those discs first came out, but they're anything but listenable music. Check out something like The Crystal Method's Tweekend album if you want something that's listenable and has enough bass to show off any system, more than a lot of those bass CDs at that. There's tons of other stuff out there too, lots of good music with tons of bass, and those old "bass CDs" should be buried forever :)

I couldn't agree more about the whole "ooh, ahh" factor of bass CDs. When it came time to actually demo the stereo, my instruments of choice were (in no particular order)

• The Sheffield Jazz Experience
• Nirvana - Smells like Teen Spirit (Gold Ultradisk)
• Nine Inch Nails - The Downward Spiral
• Telarc's Verdi
• Alan Jackson's Greatest Hits

It's kind of an eclectic mix, but if the system is setup well, all of it sounds good.

Re:Wow, flashback to high school (Other bass CDs)

[FauxReal]

So I assume that you've listened to Techmaster P.E.B. "Bass Computer" and still have this opinion of it? It's got great sound... good production and lots of interesting samples. I still love the song "Computer Love" on that album. If I could get it on vinyl (which doesn't exist) I'd play pieces of this in my dj sets.

95 South on the otherhand... yeah, that stuff is kinda asinine.

If anyone else is reading this... a recent album out that you might like that has a more electro edge to it is: Bass Junkie - "In Bass No One can Hear You Scream"

Take a five point penalty

[cprincipe]

For having the gigantic subwoofer and having mandolin music on the giant TV screen.

A far better screenshot would have been "Apocalypse Now" or even a "Quake" game.

Re:Take a five point penalty

[Racine]

Any idea what DVD that is?

Looks like home

[Allowee]

woofers like that are just like home

got them all over my place.

tubes always produce good sound, thats why I also use tubes...
and live home-alone

Biggest *Enclosure* not biggest Sub

[Null_Packet]

I hate to nit-pick, but it's a large, elaborate enclosure and not a huge subwoofer itself. Slightly more practical is the "Cult of the Infinitely Baffled".

http://home.comcast.net/~ttriff//page2IB-Gallery .h tml

Re:Biggest *Enclosure* not biggest Sub

[SpinyNorman]

Actually it reminds me of the innards of a Bose "wave" radio... I think the curved passage ways are very much part of the acoustic design, and not just an enclosure.

Re:Biggest *Enclosure* not biggest Sub

[antiMStroll]

Not sure why you say that, it is exactly a giant subwoofer, but thanks for the very interesting link. A clever use of attic space that I've never seen before.

Re:Biggest *Enclosure* not biggest Sub

[Null_Packet]

There are numerous kinds of sub enclosures, and all of them (hopefully) contribute to the acoustic properties of the subwoofer itself. As for the terminology, it's like calling the SPL competition cars loaded with subs 'a big subwoofer', or calling a desktop pc case the 'cpu'. It infers lack of knowledge on the subject at hand, and is only correct because most people identify it with the name, proper or not.

Re:Biggest *Enclosure* not biggest Sub

[acoustix]

Technically, it is a subwoofer. Many subs these days come with 2 drivers in an eclosure. This particular sub has many drivers, but it still is one sub. All of the drivers are in the same enclosure just like a regular tower speaker.

You don't refer to a 3-way speaker system as "three seperate speakers". Same thing applies here. This sub is made up of multiple drivers in one enclosure.

-Nick

Ancient Indians put the "rock" in "rock music"

[tibbetts]

If you think that that's big, you should check out the Kupgal Hill in India, a Stone Age (no pun intended) grove of boulders that were used as enormous drums by an ancient culture.

Filling Cubes

[Slowtreme]

IIASCA != Audiophile But anyway... you have a system that runs in about 20-40 cubic feet. Plus you sit 3 ft from your subs (you never even hear a full note from your subs, the wavelenght to too large). All you are getting is a massage at that distance.

This stereo is filling at least 32000 cubes. And it's not rattling the crome.

MTV Cribs

[Morkimo]

Some hip hop pseudo thug with too much money will no doubt add one of these to his crib. "Yo yo, dis right here is fo' my peeps in the hood...BOOOOOOOOO BOOOOOO BWAH."

Dear God... The Brown Noise!

[zapp]

God save us if they figure out the brown noise...

Ricky Skaggs through a subwoofer?

[Diamon]

Anyone else find their choice of demo material that's on the screen a bit odd? The only instrument visible is a mandolin, the lowest note of which is 196Hz, cut-off for sub-woofers is generally in the 120-150HZ range.

Re:Ricky Skaggs through a subwoofer?

[Kevin Stevens]

Actually, the cutoff for subwoofers is generally much much lower than that. Even cheaper best buy type subwoofers get to around 30hz. A good subwoofer will cut off around 20. I made an enclosure for a 12" shiva mkII driver and it cuts off somewhere a bit below 20 hz.

I think you are thinking of regular woofers, that generally cut off around that frequency range, though even a decent woofer will get below 100hz. I have the amp on my sub to pick up around 120hz, though my main speakers are rather small.

Re:Ricky Skaggs through a subwoofer?

[Diamon]

Perhaps I'm using the wrong term. I'm referring to the fact that the highest frequency you would pass to a subwoofer is lower than the lowest frequency a mandolin can produce.

If your subwoofer is set to reproduce sounds in the frequency range of 30-120Hz and the lowest note of the mandolin is 196Hz, the sound of the mandolin will never go through the sub. Although technically there are some subs that will go to 200Hz available from www.crutchfield.com, even those would only be used for one note playable on the mandolin (G3, the next note is G#3 at 207.65Hz)

Re:Ricky Skaggs through a subwoofer?

[Kevin Stevens]

yeah youre right, "cutoff" can go both ways, but in reference to subwoofers it always seems to reference the low end. Most decent main speakers can get low enough that you do not have to worry about the high end of the subwoofer's response.

Either way, a mandolin is definitely *not* going to show off his subwoofer.

Similar

[Chuck Chunder]

Except those floor panels are ~1 ton of marble! From the looks of it most of the horns are under 20cm of concrete and it says about a ton of marble covers the access point.

That said it's not a flaw, they obviously are there for a reason. These people are clearly willing to go to quite some lengths to achieve a special effect so lifting up that marble if you have to is just part of it.

amplification

[preposterity]

I wonder what they're using to drive this thing.

Even a class AB amp to drive all those woofers would take up a huge amount of power...

Done before - at the New York Experience Theatre

[vtweb]

This has been done before- The "New York Experience" Theatre in New York City had a 26 foot horn Sub-woofer built beneath the floor of the audience.

It no longer exists, but was on 5th avenue in the basement of the office building for a book publisher. In the 70's I was given a tour by the operators. The theatre was housed in space that had been built to be used as a small planetarium, but had not been completed. A seating floor was built at the base of the dome, and the speaker was built in the space below. The show was a multi-screen multi-media production giving a virtual tour of NY, with physical props included.

The speaker was an exponential horn, 26 foot in length, and used twice during the show (once was during a subway station scene, I forget the other). The cones of the drivers would only last for about 4 hours of operation, so would have to be reconed every few so many shows. The was built of wood, and curved so that the opening pointed up towards the feet of the attendees.

Having attended the show many times, (early geek destination in NY), I can attest that it was an intense experience, sitting in the opening of such a speaker.

Back to the Future

[StrandedOrg]

The speaker in Back to the Future is now my second favorite speaker. =)

Girls best friend

[l0wland]

Wow, that thing must be the biggest vibrator in the world! Eat your heart out, Harley-Davidson!

Finally!

[StormyMonday]

They've eliminated all those annoying mid-bass, midrange, and high notes.

Nobody cares about anything but bass, the lower and louder the better.

That's music!

and Back to the Future, any more media w/ big

[aaron_pet]

Marty Mcfly would blow up those speakers so quick

but then he might not be alive to go introduce his dad to his mom...

(I know it's corney to reply to my own message, I have have a theme going here)

How will an MP3 recording help?

[TigerNut]

Recording the sound produced by that and then compressing it to MP3 (and playing it back on some tinny sound system) is unlikely to give anything even close to what it's really like. You'll just have to book a trip to Italy...

Re:How will an MP3 recording help?

[Anonymous Coward]

To you, humor is just something that other people experience, isn't it?

I wonder if...

[haggar]

I wonder if, by hitting the correct frequency, they could collapse the building. "Dude, that music was POWERFUL!"

10Hz? I've seen a CD do 1Hz!

[Anarchofascist]

In the dim dark past a friend of mine got hold of a CD for testing CD players which had a 1Hz tone. The speakers slowly moved in and out as I watched...

Re:10Hz? I've seen a CD do 1Hz!

[Anonymous Coward]

I raise the bullcrap flag. You probably thought you saw the speakers moving in and out...

Re:10Hz? I've seen a CD do 1Hz!

[Anonymous Coward]

I uses to do this with an ampeg bass amp and an 18" sub I had wired in. you could grab the E and move it and watch the sub cone move.
I miss that amp, I've tried other amps but after a month at 11 they all turn to mush (Peavey lasted a week, cheap crap!)

Re:10Hz? I've seen a CD do 1Hz!

[Tackhead]

> I raise the bullcrap flag. You probably thought you saw the speakers moving in and out...

I wonder what speakers playing either a 29Hz or 31Hz tone in a fluorescent-lit room would look like :)

Re:10Hz? I've seen a CD do 1Hz!

[Anonymous Coward]

man, if anything ever deserved an insightful mod... good call.

probably within the last decade at least...

[SethJohnson]

Hey---- Check the big-screen tv. In the seventies, I think people were maxing out with like maybe 19 or 26" tv sets.

A lot of older technology like tube amps and turntables still are the audiophile's best friend. These guys are using tube amps, but CD technology..

all your bass are belong....

[cudaboy_71]

oh nevermind.

They hate it when...

[kabocox]

folks like me walk in and say that I can't hear anything different from my $30 walkman.

Cross your legs

[buckeyeguy]

Better hope these guys don't plug South Park's "brown noise" into this beast.... or there's gonna be a lotta Mr. Hanky.

I was about to yawn....

[jeddak]

...when I noticed the video of the mandolin player. Now that's the first instrument I'd think of when setting out to test a gigantic subwoofer!
hee!
But a very cool project. Bet they could make the building fall down with the right resonant frequency....

That ain't nothing...

[niktesla]

after surviving a Damage Area concert - the galaxy's loudest sound!

We called it "A Bong"

[da5idnetlimit.com]

and you wern't limited to sake, either 8)

Ease of maintenance?

[Hoi Polloi]

From the website:
"Compression Chamber finally closed and covered with nearly 1 ton of marble"

God help them when they need to do any maintenance. Hope they never have a big spill or flooding.

DVD and CD would actually be better for this sub

[stereotype441]

Note that you won't get the full range of the subwoofer with a DVD or CD. Both have a bottom limit of 20 Hz, while the sub in question can allegedly output down to 10 Hz flat (and well below that with fall off).

Actually, CD's are perfectly capable of carrying frequencies down to 0 Hz, as are Dolby Digital encoded DVD's. I don't know first hand about MP3, DTS, or MLP, but there's no reason they wouldn't go down to 0 Hz either. The reason is bandwidth: since the range of frequencies between 0 and 20 Hz is so tiny, they take up a very small number of bits in the bitstream. It would take extra work to exclude those frequencies from the format, for no tangible gain.

LP's, on the other hand, pick up a lot of ultra-low-frequency noise that's not on the record (trucks going by, warping of the record itself, etc.) Any phonograph preamp worth its salt will filter out anything below about 20 Hz to prevent those noises from getting to the speaker and distorting the rest of the audio.

Simpl answer

[the_twisted_pair]

He'll not be blowing things driving this with 6w tube amplifiers...

Note the extreme sensitivity of the speaker, 110dB/W. That's about 16% efficiency in conversion of electrical to acoustic energy, or 20dB (c.100 times) more than even good hifi speakers. High sensivity gets you natural dynamics and musical subtlety, which the usual approach ofhonkin'-great-poweramps into insensitive speakers is usually rather bad at. Once you've heard what horns can do, when you absolutely, positively gotta shake every mother in the room - accept no substitutes.

Look, this is one (extreme!) take by a bunch of guys into sound quality, not quantity. I bet this thing will sound sublime at realistic levels - all from a flea-power amplifier.

Another giant subwoofer

[Anonymous Coward]

I built this one for burning man last year:

The MemeHorn

even though it was built close to ideal curves, it didn't work as well as I'd hoped. Granted, I was in open space with no room reinforcement and it wasn't built of very heavy material, but it certainly did give me quite a crash course in audio engineering and the many problems and trade offs that you have.

If you've never listened to a good horn loaded-tube driven setup you'll be amazed at how clean and pure they can sound.

Now that we have our giant subwoofer....

[Fizzlewhiff]

Let's break out the mandolin. I don't think the mandolin is the best thing to test out the bass with. Maybe if they were building a giant tweeter.

zero feedback...

[the_twisted_pair]

..means zero time delay around the amplifier FB loop trying to correct its own output. There is a school of audio-taste that holds the lack of 'smearing' effects is worth the higher-on-paper distortion, because the musical message of the performers playing in time etc. is better preserved.

I think their wrong, but at this level, it's all about taste (or lack of).

Game On!

[Anonymous Coward]

Dude!

Unreal 2004 LAN party at HIS place!!!

That reminds me...

[JasonMaggini]

Marty, you might not want to hook up to the amplifier. There's a slight possibility of overload.

Better Uses

[missing_hed]

I bet this chamber would add a whole lot of value to game play as well. Hook your PC up to that mother and let fly with some battlefield or UT2004... give rocketjumping a new aspect of reality, your couch will be bouncing with every explosion.

Re:For a direct-radiating subwoofer, check this ou

[Anonymous Coward]

..their Main Autosound2000 website)

Good grief, get that website a competent designer and a text editor!

Now all he has to do...

[vudufixit]

Is lower the springs on the house and install a kit that will make it bounce up and down.

Brass & Trumpet

[acoustix]

The brass and trumpet sounds are made by reed pipes. It only takes one pipe to create the sound.

-Nick

Re:Brass & Trumpet

[Anonymous Coward]

The brass and trumpet sounds are made by reed pipes. It only takes one pipe to create the sound.

There is still one pipe per note on the keyboard. 61 keys, 61 reed pipes.

A brass instrument makes different pitches by a combination of the player altering his embouchure and pushing the 3 (or sometimes 4) valves. A pipe organ can't control embouchure. Brass pipes in an organ don't have valves. Hence, one pipe per pitch.

You're welcome.

(ps, MOD PARENT DOWN for misinformation!)

Doesn't hold a candle...

[jlanthripp]

...to the system in a yellow Ford Ranger pickup truck driven by a ridiculously obnoxious teenager who lives down the street from me.

And yes, I've been hot-loading some 7.62mm (.308 Winchester for the metrically-challenged) rounds for the next time he drives past my house at 2am.

Re:Doesn't hold a candle...

[tono]

Actually 7.62 and 308 winchester are different rounds. 7.62x39 is the same round used in AK47s, mini-30s and other fun rifles of the sort. 308 winchester will not work in these rifles. same caliber, very different round

Re:Doesn't hold a candle...

[Anonymous Coward]

Didn't mean 7.62x39, the round used in AK47 and Mini-30. I meant 7.62mm NATO, AKA .308 Winchester, which is the round used in the FN-FAL, M-60, and many popular bolt-action deer rifles.

And to the clueless mod - There was a total of *one* reference to thump-mobile idiot car stereos in the replies to this story when I submitted mine. Said reference was to the effect of "Can't wait to put this in my car!"....or are you the piece of shit inconsiderate asshole in the yellow Ford Ranger?

Re:Giant American Evil!

[Anonymous Coward]

Considering the goal of all good muslims is to be a suicide bomber, i say kill them all.

Cheaper alternative

[Crazy Man on Fire]

You won't get sound as good as what I'm sure they have, but this design is a bit more reasonable for the average home (and budget). From the article:

Most woofers just don't quite do the lowest octave. You read the specs that say "usable response: 20 Hz - 20 KHz" and you know that the 20 Hz part of it is wildly optimistic. Achieving very low frequencies at reasonable power levels is not an easy job... Let's face it. Size does matter. El Pipe-O consists of very large woofers mated to large cylindrical transmission lines. The goal is to get good powerful response down to 20 Hz at levels where the room starts to rattle before the loudspeaker.

Re:Cheaper alternative

[Doesn't_Comment_Code]

Thanks for the link.

I just got done reading it... and now I want to build another set of speakers. And that's bad because I have a lot of stuff to do right now. Maybe I'll just build a little one...

Re:Cheaper alternative

[Crazy Man on Fire]

I get the same feeling every time I read that article. I found it about a year ago when I was looking into building my own audiophile amp. Just thinking about the sound that those things must produce makes my knees go all weak.

Great way to attract snakes!

[PDX]

Slithering your way soon.

human subwoofer

[BinLadenMyHero]

Once I went to a party where a eletronic music band was going to make a live performance.
But some equipment broke, and at some time they starting improvising some acoustic percussion, and they even managed to make a funky sound, people started dancing, and some even joined the band.
Feeling that a big booooom bass was missing, I started jumping on the wooden floor, marking the bOOm-bOOm-bOOm-bOOm.. it was very fun. :P

correct - had a DAT that recorded DC.

[morcheeba]

Yep, that's correct. I worked with a professional DAT player that went all the way down to DC. Of course not all DAT players will do this, and many people would consider it a flaw (since, for music, a DC offset doesn't produce any sound, but will make the A/D clip at a much lower volume).

We used it to record serial data, either as analog from the satellite, or digital after we'd sampled it, and both worked. Of course, to record RS232, we needed to keep the level in check, but the output looked square on an oscilliscope.

How about a 6 foot driver...

[mcglothi]

I was thinking of Richard Clark's experiment:

http://www.autosound2000.com/gallery/images/Richar d3-sml.jpg

Shortcoming

[Anonymous Coward]

Yes, the inability to levitate in midair. Maybe level a building...
You related to Freud or you just want to be annoying as he was? Freud was actually about a lot more than just sex, however most people seem to focus only on that part.

Re:Done before - at the New York Experience Theatr

[AndroidCat]

Did they ever test it for the rumoured .. relaxing .. effect on certain rear muscles at 11 cycles or so?

Re:Old News: Not must it IS old

[Anonymous Coward]

I saw this about 5 years ago. People who were into speakers before then probably heard/saw even before that.

A good match for Klipschhorns

[psgalbraith]

The sub would be a good match for Klipschorn speakers or Klipsch's movie theater series.

But I guess they are competitors.

Transistor Beta

[Detritus]

I believe negative feedback is also used to reduce the effects of manufacturing variations of transistor beta (gain) on the performance of the amplifier circuit. A handful of transistors, even with the same part number and manufacturer, can exhibit wide variations in beta from part to part.

Nothing extra

[rudib]

Check these Infinite Baffle designs, especially this one.

IB is actually the most simple and cheap DIY solution if you have an appropriate pair of rooms. Also, it gives the best bass sound reproduction, better than the usual box/horn designs.

A great DIY/Pro horn subwoofer design is the LAB subwoofer. "A bit" big, but with great sensitivy.

Mod me troll if you like

[Anonymous Coward]

...I've seen enclosures that more closely resemble a loading horn, and use less hardware for clsoe to the same efficiency (and a lot less maintenance issues). Why didn't they just use one 30" woofer and a folded transmission line?

it's not a giant subwoofer, it's a giant enclosure

[iamhassi]

From the article:
"Royal Device has on its own developped and built the biggest subwoofer of the world... SUBWOOFER horns are built underneath the floor in a cavity of 1 meter deep. Each horn is driven by 8 x 18" (47 cm) woofers. "

18"? That's a pretty common size, nothing special there.

Only thing this guy did different was dig a pit and put them in there, making a giant enclosure for the subwoofers.

A subwoofer is defined as a "A subwoofer is a loudspeaker device which reproduces sub-bass frequencies below about 80-100 Hertz" and a loudspeaker is defined as a "a fibrous semi-rigid cone and attached to the apex of the cone is a coil of fine wire (usually copper), called the voice coil or moving coil." So according to the definition of "subwoofer" all he has is 18" subs, not the "biggest subwoofer of the world" by far.

What he has is the largest enclosure, and I'm not even sure if that's right because there are many theaters and amphitheaters designed from the ground up to amplify and direct the sound of bass frequencies which is really all that his enclosure does.

They guy also claims to have the "the biggest AUDIO ROOM for private music listening of the world", but at 6.95 x 8.70 meters (22.8 x 28.5 feet, ~650 sq ft) I have my doubts about that claim too, especially since it has a lcd projector in there so it would have to compete with all those privately owned theaters. I've read that Bill Gate's house has a 1,500 sq ft theater, triple the size of this guy's "the biggest AUDIO ROOM for private music listening of the world".

Re:The "Biggest"...why?

[p51d007]

Same reason some people spend on lots of things......small penis size! LOL There money.......no biggie to me......a fool and his money are soon parted ;)

hmmmmmmmm.......

[Macrolord]

The guys obviously don't have kids: This system is simply not PB&J proof. ....Besides, they don't have an output stage modded VHS player so Barney can be on the big screen.

Oh and also...The page refers to a CDP. ...as in a CD Player?
So how do they synchronize the video to the audio?.... or is that just a slide projector with pause "spelti funni".

Bass pump without a sump?

[Anonymous Coward]

It would suck if he got water in the basement. I'd have sloped the whole thing away from the speakers, dug a hole, and put a sump pump in, along with a vibration dampening assembly to support the pipes, and a de-humidifier with a humidistat.

This is why it is recommended to get the advice of a building contractor when doing this sort of thing...

He will pay one day. Based on the gear in that room, I'd use a high capacity pump.

l8,
AC

Where's the plans

[BluedemonX]

For the homemade LAW rocket I'm going to use when some cretin starts driving down my street at 3am blasting some of that garbage bass-heavy rap music through one of these things?

Sure, he might be towing it behind his sticker-laden Honda Civic cause it won't fit, but to the Eminem clones of the world such things are mere details. You hearing the latest "joint" by MC Murder Diggy Dogg is far more important.

Sub-performing in other areas...

[Toadee]

How diminutive in the mommy and daddy department do you have to be spend money on this type of thing?

The opposite approach: Motional Feedback

[MZdoctor]

MFB drivers have an acceleration sensor and a FET fixed to the centre of the cone. The power amp and power supply are inside the enclosure. The sensor signal is compared with the input signal and the result is LF reproduction that is a) perfectly linear down to any desired cutoff frequency and b) unaffected by changes in mechanical and electrical properties of all components.

I have a miniature set (4" driver, 8 litre, fully enclosed, 2-way) with -3dB point adjusted to 20 Hz that has kept me drooling for almost 30 years now. Obviously the acoustical pressure is limited by Doppler distortion but the quality of the LF reproduction is such that I am completely satisfied with the modest available sound level. Larger versions were also made at the time but the market rejected the idea so Philips pulled the plug on it. Fortunately these things seem to last for ever. They can be plugged into any headphone output. There is even an MFB owners club!

Re:The opposite approach: Motional Feedback

[Anonymous Coward]

google's cache has an interesting article about a speaker installation system using Motional Feedback, with an unflattering reference to Phillips Motional Feedback system:
http://66.102.7.104/search?q=cache:bNVt5PxCxL8J:ww w.meyersound.com/news/press/sos_x10_800.htm+philip s+motional+feedback+driver&hl=en&ie=UTF-8

The Italian Job

[keller999]

We've finally found it - the system with the ability to blow women's clothes off.

only 2 true 64' ranks in the world

[Anonymous Coward]

Diaphone Profundo 64 in the Atlantic City Convention Center
Contra Trombone 64 in the Sydney Town Hall

There are a couple of others that don't go all the way down. And a whole bunch of "fake" ones.

incidentally, the one in Atlantic City is known as very expensive wind. (since you can't really "hear" 8Hz)

Then there's the Subgrossuntersatzregalbass. mwah ha ha ha

Re:only 2 true 64' ranks in the world

[PalmKiller]

ouch, that had to hurt

Re:DVD and CD would actually be better for this su

[forkazoo]

Well, first off, frequencies are continuous, so you can't count the number between 0 and 10. It's the same as between 10 and 100, or 10 and 10.25. Further, why do extra frequencies take up extra bits in a bit stream. A simple raw audio format, like you'd find on a CD is just a simple Intensity = sound (time) type setup. Lots of samples of what the voltage on the mic was at a particular instant. You'd need to do a Fourier Transform to see the frequencies.

Now, that said, I think I basically agree with you. There isn't any fundamental reason why one couldn't make a CD which is an hour long, and contains exactly 1/2 cycle. With only 16 bits, it'd be far from perfect. 65,536 individual steps means that you can have a little lower than 1/2 Hz (44 kHz sampling rate means a little over two seconds to go all the way down and all the way back up as a Triangle wave.) If you accept either doubled samples, or dithering, then you can stretch things out arbitrarily. If you did that, you could have the speaker moving so slowly you could see it plainly. OR, so slowly it would look at a glance to be perfectly still.

This would never happen on recorded music, as no mic will pickup 1 Hz very well, and the recording studio would probably just filter it out anyway, as it's probably just noise.

Headphones?

[spamnix]

So, um, when are they gonna build that subwoofer assembly into headphones?

On custom amps..

[Stomple]

This setup may be big, but mine goes to eleven...

Re:Done before - at the New York Experience Theatr

[Jim Starx]

I was always told that was at 4 Hertz....

huge wooden speaker?

[Fredbo]

It'll take alot of sake to make a wooden speaker of that size!

Someone tell me how you get more real than real

[BrianDeacon]

From the article:
"In this conditions, peak levels are much higher and undistorted than any live concert at all."

If he's saying that "it sounds more like being at the concert than being at the concert" then I'm just going to write it off as a sales pitch. But I'm betting this is more a case of my ignorance. And what better place than /. to have your ignorance pointed out? :)

So someone enlighten me... what is he really saying?

B

Re:Someone tell me how you get more real than real

[cavac]

Well, at concerts there is a legal limitation on how loud the band is allowed to play. And you're certainly not allowed to more or less put your head into a subwoofer destined to be heard by 10.000 people.

I personally expect that you have to have bad hearing for a start to appreciate the sound - otherwise your brain may get scared and jump out of your skull in self defense. Hell, even old-aged Mozart - death as a post - wouldn't have had problems hearing that thing, i guess.

Anyway, i curious: How do they protect against accidents? A sound system that powerfull *must* be protected against unwanted sounds like clicks and whines...

It is Old, on www.hometheaterforum.com anyways.

[Cordath]

That page has been posted again and again on hometheater forum. It's been around for years, but gets occasional updates. It is a cool sub, I must admit, but I had to stifle a laugh when it showed up on Slashdot. It's definately for audio nerds, but it isn't news. Not by a long-shot!

Re:Done before - at the New York Experience Theatr

[UrgleHoth]

Your comment reminded me of the movie Matinee

If you're not familiar with it, it stars John Goodman as a B-Movie director. To promote his flick, He set up a Florida theater with "Rumble-Rama," a device to shake up the movie house during disaster sequences.

If you mean "driver", say "driver".

[Anonymous Coward]

No, you're wrong. Do you think "driver" is synonymous with "subwoofer"? It is not. A subwoofer is a "black box", capable of generating low frequency audio. It needs to push air. How it does that is not important to calling it a "subwoofer". It may use one big driver. It may use a bunch of small drivers. It may have a huge enclosure. It may use baffles inside the enclosure. It may have a port. It may push air without any traditional driver at all, in a way not yet invented, yet I would still call that black box the subwoofer. Wouldn't you?

Here's a test for you. I give you a big black box. You don't know what's inside. It plugs into AC power and also takes its inputs from the speaker output of your amp. (You can run it in parallel, off the "B" outputs, or off a completely separate amp, if you like.) Anyways, you hook it up and find that when your system is playing sound, it outputs the low frequency component of the source (say, from 15 Hz to 100 Hz with a nice flat response curve) with SPLs proportionate to your existing speaker system. Do you consider this a subwoofer because of what it is doing, or do you have to open it up first to confirm that there is a recognizable driver of some sort in there first? Me, I consider this black box a subwoofer regardless of how many of whatever it is inside.

The Hottest

[DynaSoar]

Not as large, but probably far more impressive to see in operation was a subwoofer contructed at Purdue University. A single 12" driver was attached to the bottom of a large vertical gas burner, essentially an enormous Bunsen burner. When turned on the flame was 30 feet tall. The driver modulated the air going in and the flame surface acted as the woofer. It did 1 Hz with no appreciable distortion. Of course, only the instruments could tell for sure.

yah but...

[nappingcracker]

wheres the megabass?

That is not motional feedback

[MZdoctor]

Thanks for the reference. Note that Meyer's design involves measuring the air pressure in front of the cone with a microphone, and that on a reflex system where lots of sound is bypassing said microphone. This is a far cry from Philips' KISS design philosophy and cannot be classified as motional feedback. No wonder Meyer says "this is a very complex problem to solve, and one that has defeated all previous attempts"! However MFB does not constitute a "previous attempt" to solve the problem he set himself.

I am aware of the discussion about the perceived quality of sound reproduction of Philips' MFB range, but chose not to bring it up as it would take us off topic. Actually the closed loop motion control only operates up to 500 Hz and the 4" driver carries on passively up to the crossover point at 1500 Hz (also passive) where the tweeter takes over. In other words the MF and HF department is uninteresting. However the LF and especially the VLF part remains unique and I feel that the fundamental principle (i.e. that of true MFB) still has unexplored potential.

Meyer qualifies Philips' attempt as "disastrous" and "underwater sound", Would you expect praise from a competitor? Hands up all Slashdotters who have actually listened to a set of MFB speakers....

Sound delays

[relaying denied]

Wouldn't there be a considerable delay with the long horn setup? Especially in such a small room... I saw no mention of them using any processing to control timing. If anyone cares to explain it either way, it'd greatly appreciated.

Neighbors will be surprised

[just_cc]

The neighbors will be surprised if you hear loud ;-)

In the 70's there was "Earthquake" the movie

[pair-a-noyd]

(the 70's was fraught with disaster movies..)
and the theaters installed super huge sub-woofers for the effect. When the quake hit, they lit off the sub-woofers with sub-sonics that literally made you shit your pants in terror, not expecting it of course, and no one had ever experianced sub sonics like that before. It was awesome. The speakers were trucked from theater to theater in a semi along with the reels.

A few years ago, one of the local theaters folded and they tore it down. They still had a set of the "Earthquake" speakers there and they THREW THEM OUT. I would have picked them up and brought them home but I didn't have a truck at the time :( There must have been $1,000 worth of hardwood plywood in those boxes...

Damn...

OLD NEWS

[pbjones]

this article is 4-6 months old, I'm sure it has been on /. before, 'cause I have seen the pics before. yawn is restarted.....

Idiot.

[Anonymous Coward]

Uhh, you can't call yourself an "InsaneGeek" if you don't even know how to make a damn hyperlink. Fucking moron.

Re:Idiot.

[InsaneGeek]

Whatever. I don't dumb down myself for gui world, so go back to your M$ point and drool land because text is obviously too hard for you.

Am I too late for the 1.21 Jigawatt reference?

[AbRASiON]

This is kind of cool, but I was thinking it was going to be one bigass sub not an enclosure.

Anyone got links to the biggest sub? - I think I saw a 3' one linked on a site recently.

And the first song he played?

[Any Web Loco]

Stairway to freaking Heaven.

Impedance Matching

[wabbit3.0]

Horns are basically impedance matching devices. Anyone who has heard an old gramaphone has probalbly noticed that the sound can be quite loud. The horn matched the acoustic impedance of the needle to that of the air. These are equivalent to tapered lines in microwave and RF work. Pipes (e.g. organs) are the acoustic equivalent of transmission lines, and again act to match the source impedance to that of the air. Baroque organs could fill a church with sound will very little air pressure driving the pipes. The Bose wave radio uses a internal pipe as a transmission line match. You can make you own version out of PVC pipe. One problem with transmission line matchers is narrow bandwidth. The old solution was to stuff the line with some material to lower the Q. Bose seems to use some DSP tricks There are a number of web sites out there on transmission line sub-woofers - don't have the links handy, but google should reveal a bunch of projects for anyone interested in a cheap and efficient base source.

Perhaps. . .

[Makoss]

Perhaps they are in stereo so that the left/right channel information in a stereo recording does not ahve to be combined into a single waveform before being output. This should result in a cleaner audio path, and if you're building that crazy of a sound room, no detail is too little. . .

Or it could simply be for reasons of output. Two horns would get you ~3dB more at a given power per speaker.

As for the recording. . . .yeah, I've gotta agree with you, you have to use non-standard things to record that low with any fidelity. But ya know if you've got the crazy system you'll probably be able to find SOMETHING to play on it. . . .

And I know a few DVDs have effects that go below 20Hz.

Demoing a mix

[ce25254]

Headphones in a recording situation do have another use. Headphone listening can be pretty useful in evaluating a mix, if you want to know what it will sound like for a listener on headphones. Also car speakers, and cheap jamboxes.

OLD news

[UnknownSoldier]

For anyone who hangs out at the excellent Audio/Video forum

The problem with non-movable bass, is that if you have sound nulls, you can't really do much about it.

And of course, like any good subwoofer array

[br0d]

chicks will end up sitting on it and pretending they're just "relaxing"

SIK!

[Anonymous Coward]

MATE!

FEEL IT BABY!

[Lotharjade]

If a note is lower than the 20Hz, can you feel it? If so, that might make it usefull in a stadium to EXPERIENCE the sound.