Slashdot Mirror
Build Your Own Subwoofer
Gerard J. Pinzone writes "Here's a page that details the construction of a homebrew subwoofer." Another in a long line of "You can, but should you?" projects.
← Back to Stories (view on slashdot.org)
← Back to Stories (view on slashdot.org)
the days when you HAD to build your own car.
"linux is only free if your time has no value" - Jamie Zawinski
I thought it said build your own hebrew subwoofer!
Fat people are harder to kidnap.
He only built the enclosure ... I was expecting a 50Mb AVI of the guy winding the coil and magnetising the magnets.
I just want to see how he hacked a router to do that.
Kidding...I'm not that much of a geek.
I would have loved to see him try to build one out of parts of a microwave, stove, dishwasher, and drying machine while using a fridge to house it.
See what happens when you have old episodes of MacGyver on tape?
/^[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,4}$/i
They are pretty simple to build and for $80 you can have a subwoofer that will make your whole body shake. I've seen it done.
How is this news? I like the article on how to do it, but I people have been building subs for a long long time. You can go to radioshack and buy everything you need to build a good sub. Optimus is not the greatest but Im sure you can get the encloserment and then go to a good speaker shop to buy a 12" sub speaker. Plus the 4 gage wire and blah blah blah.
Oh well. Cool article!
keanmarine.com
where xxxxx is some computer software thing. now
since this project uses wood and screws and drills,
slashdotter is gonna think 'oh my god! how do they do that'
but to people who do that sort of thing all the time,
this project is as though a throw-away perl script.
given a little basic wood and wood tool knowledge
this is not a humungous project (unlike
all the stuff that gets plastered
on freshmeat and slashdot every day, like
KDE, gnome, debian, redhat, and hundreds of
other projects that take inordaintely more
time than this project did)
Tumb!
This is some guys expierence making an ENCLOSURE. I got excited, wrapping a cone w/ wire, finding a good permenant magnet. NOPE - This is something that MANY MANY people have done. It is making a subwoofer that would be the challenge. Then again, making a proper enclosure isn't easy...
Next time get the title of the article right!
I was hoping this would talk a little more about the mechanical aspects of building the actual driver, instead of being mostly a guide to fitting a sub into a box. Or am I just missing something?
Here's another guide for building your own subwoofer.
The DIY section on avsforum also has some info.
DIY subwoofers is another place to start.
In fact a google search yields about 16,000 results with the words "DIY" and "subwoofer".
Which brings me to...
Is this really news?
-S
--- What parts of "shall make no law", "shall not be infringed", and "shall not be violated" don't you understand?
Subwoofers are one of the few things that home audio do-it-yourselfers can build that is at least somewhat cost-effective in terms of material, effort, and result (well, maybe planar ribbon loudspeakers, though the lines of magnets might be a bit of a pain). Put a nice, massive driver and bandpass filter into a well-dampened box of appropriate volume and spousal approval and you'll have something that not only adds to the depth of music, but will also give you a martini "shaken, not stirred" during your James Bond movie marathon. :)
This tagline is copyrighted material. Please send $10 for an affordable replacement.
its not that uncommon to build your own stereo equipment, people have been doing it for as long as there was stereos. In fact most car stereo junkies I know of build their own speaker boxes as it is much cheaper then paying someone else to do it and chances are will look better as it matches the look of your car. Had the guy made his own speaker I would be impressed
It must be a rediculously slow day for geek news.
There is a strong and thriving community of DIY audio enthusiasts. I myself built my own tube preamp, interconnects, and power amp. Try http://www.speakerbuilding.com/ for information about building speakers. For broader information, go to http://www.stereophile.com and click on "Links 2 Die 4" (the l337-ness is theirs, not mine) and then on the DIY link.
WTF does this have to do with anything intresting?
Every 16 year old with a ride builds his own for his car. You know... boooommm boom boom boom boooommmm
;-))
If they can, you can too. (And if you *can't*, please turn in your geek badge right now
Besides, your (legal, of course) MP3s and Quake III Arena will sound much better with one!
---
Information wants...you to shut your pie hole.
Sure, it's great that the guy documented his project so others could replicate it, but it might be more useful if he mentioned how he calculated the optimal port length. Specs on resonance frequency, Vas, power handling, and other things might be nice as well. Or why he chose a ported sub rather than an isobaric or sealed design or something else. Not that there's a correct choice, but knowing a little bit about how and why he made his decisions might help others down the line.
This sig intentionally left justified.
People have been doing this for a long time (Building ENCLOSURES, not subwoofers). All those little bassheads that you see going down the street with civics shaking the windows out of your house do it themselves. It's simple and easy, and most companies that sell subwoofers provide very detailed and specific guides (more than that page) about port length for ported boxes, volume calculations, building materials, construction methods, and countless other things. And boy, MDF is a bitch to work with.. you need a carbide blade for the saws, and screws strip SO easily. Not to mention MDF dust is very carcinogenic (search around google) and smells bad. Expect this thing to stink up wherever you put it for a while. Most of the guides are in PDF format (For car audio) from the major sub manufacturers' sites: www.kicker.com www.rockfordfosgate.com etc Forque (Chester Bochan)
Building a sub is a great project. As a single driver speaker, it requires no crossover, and therefore is relatively easy to design/build. Plus, with some careful planning, you can get amazing results.
/.
I've built a couple Subs based around the Shiva Mk II driver this guy used, along with a 250W plate amplifier from partsexpress, and it is amazing. Easily produces useable bass down to 20 hz in a sealed enclosure (F3 of something like 17.3 hz in a 1.7 cu ft. box, if I remember correctly...). An adire sub kit easily rivals subs in the $1000-$1200 range.
Listening to one of these explains why audiophiles don't like those Sat/sub computer multimedia sets, and tend to call them a "bunch of crap". None of them produce any useable bass below 50-60 hz, and a lot of HT systems are designed such that the sub only STARTS playing from those frequencies down.
Having said that, I don't see why this is front page news on
This is where I get my recommended daily allowance of "Foot in Mouth."
But, that's OK, considering all that will do is change the tuning frequency..
Quote:
---
The ports are 4" and flared from Madisound. They came with a short tube to connect them, but it wasn't long enough. I went to Home Depot and bought some 4" schedule 20 (the thin stuff) pvc and 4 schedule 20 4" couplings. I realized after sealing the sub up that I had mismeasured the ports and made them too long. But, after emailing Patman in panic, he assured me that the only thing that would change would be the tuning frequency.
---
So much for frequency response..
That's nothing special is it?
You can buy your own plans for tubes or boxes all over the place.
A subwoofer is the actual speaker which he just popped into place right?
You can even download software to help you download dimensions:
subwoofer enclosure software
The man who trades freedom for security does not deserve nor will he ever receive either. - Benjamin Franklin
There's more to building quality speakers then just mounting drivers in a box: particularly with ported designs. Building a sub with controlled, tight bass is the challenge; anyone can build a deafening "rumble box".
-Chris
--an unbreakable toy is useful for breaking other toys--
given the low price for a system these days and the crap sound you'll get if you do it wrong, buy an iSub and a couple of sound stix at the Apple store and save yourself a couple of years of apologising for the crappy looking cabinets.
MSBPodcast.com The opinions expressed here are my own. If you don't like 'em... Think up your own stuff.
This isn't even a good explanation for how to create a subwoofer enclosure. It is completely missing any information on the critical variables that describe the attributes of the low frequency driver as well as the procedure for designing the enclosure and crossover network to work with the driver to produce an optimized system. You can't just throw any old speaker into a given enclosure and expect a decent result. If you don't design the enclosure around the Thiele-Small parameters for the driver you put in it you are basically throwing the driver into a pretty box and ignoring the most important factors...how the completed system will perform.
And I wouldn't be a good slashdotter if I didn't mention are several computer programs that help with the design of speaker systems. They are really helpful for designing a subwoofer. I used such a program to design the subwoofer in my car.
Oh, and they are an Internet sale only company - you buy subwoofers directly from them, there are no other dealers between you and them.
And I don't own a SVS ... yet ^_^ (and neither do I work for them)
He did not build a sub, he built a box. There is a big difference. If anyone is interested in a custom made sub, do a web search, Richard Clark built a sub with a diameter of over 50 inches.
There isn't anything special on making a woofer by yourself, first i thought that the dude made the element by himself but naawh... You really don't need much skill to make a subwoofer, just some maths and a little skills to make the casing. If you have proper tools it shouldn't even take long for an experienced woofer builder. With experienced i mean knowing the little tips & tricks to avoid hazzle and problems. tho, that woofer probably sounds nice but there isn't anything special... i wonder where ./ is going with news like this, do they wanna do a news report when i assemble my next woofer? lol
Or perhaps some of my other projects like liquid cooling to make cpu run at -15 to -10 celsius degrees, or perhaps mobo box sized server...
NOTE TO MODDERS: I didn't want to troll but there simply isn't any idea to report stuff like this, there isn't anything special on making a subwoofer by yourself.
Pulsed Media Seedboxes
When i first read the title to this story, I said to myself, "Wow, some guy actually hacked together some magnets and other supplies and built his own subwoofer!" But it's just an enclosure!
/.
:P
Wow, so what he built his own enclosure. This is common practice in both home and car audio and hardly worth the post on
I build an enclosure for 2 subwoofers for my car when I was 16 years old. It's not hard, and there are many MANY pages just like this one out on the web.
Another in a long line of "You can, but should you?" projects.
Well if you can handle power tools, and a couple of simple caculations to get the right enclosure and port size for your subwoofer, then HELL YES! I still have mine in my car that are custom fit, and sounds better than the cheap enclosure i had before. I even used pvc pipe as the ports
Imagine a beowulf cluster of these!! hooo-yeah baby!! uh uh uh love that pussy!!
mje0w!!!1!
Just take a gander at the king of all subwoofers they made out of an old hard drive motor at MIT!
Software piracy is victimless theft.
... where are the Lego guys?
I own the 4th and 5th editions of this book, and it has everything you would ever want on enclosure design. You can pick it up from Crutchfield, or I'm sure Amazon, Barnes and Noble, etc. should carry it.
Overrated / Underrated : Moderation
Now that is building a subwoofer!!
might as well get 15' of 10" PVC put a 10" woof appr.2/3 the way down(go get specs yourself) and get bass to stir your guts.
*Repent!Quit Your Job!Slack Off!The World Ends Tomorrow and You May Die!
They have no enclosure!
Regardless, why is this a big deal? I used to build boxes back in high school. They usually sounded awful but not always. Just had to get them sealed up and calculate the dimensions properly.
I had two JL 10W1's that sounded pretty good for a relatively cheap speaker.
The man who trades freedom for security does not deserve nor will he ever receive either. - Benjamin Franklin
One 26 inch home-brew subwoofer, coming right up!. They built it with the driver from an ancient hard drive. For those not up on Norse mythology, moljnir (several spellings seen) was the unstoppable hammer of the gods, carried by Thor himself. I'd say a building-shaking sub comes pretty close to that description. ;-)
News for Geeks in Austin, TX
This is an article on how to build a sub box, not the speaker itself. Many people build their own sub boxes, this is a pretty nice one from what I can see, but its not much different then whats in the trunks of many people across the world today..
you can, but why fucking bother?
sigh.
sometimes DIY is not better. if your time is worth $50 an hour, spend it better buying one if it takes more than an hour to make one. don't be a jerkoff.
There are many fine sites out there with information on building subwoofer enclosures. While the construction of this one was fairly robust and adequate, the design will likely have a very poor response. There are too many no-no's here to cover for a SlashDot comment. Y'all should try some real sites for a start:
CD Racks - Methods and practices of mounting on walls.
This is *BOOOOOMMMMM*cool cool, I think *BOOOOOMMMMM* i'm gonna try it *BOOOOOMMMMM* for my home *BOOOOOMMMMM* theatre!! The low end *BOOOOOMMMMM* would add a *BOOOOOMMMMM* lot to the experience *BOOOOOMMMMM* .
J *BOOOOOMMMMM*
*BOOOOOMMMMM*
Beer, now there's a temporary solution -- Homer Jay S.
I'm no acoustic engineer, but it seems you'd have to do some calculations to make sure the resonant cavity matches up to the speaker. I don't see any evidence that he's done any calculations whatsoever. How would you go about determining the optimal size and shape of the cabinet? Or does it not matter on such low freqs?
This has to be the worst Slashdot how-to ever. There is absolutely nothing geeky about doing it blind like this, especially considering how much information is available about doing it the right way. So kids, don't do this at home; do better!
What? Do you think this is for listening to MUSIC or something?
This poor chap must have thought "I don't need no stinking math, for a living I'll build custom subwoofer enclosures and sell them!" Now you're telling him he needs math for that too.
With the knowledge that I'm being redundant, this is perhaps one of the most irrelevant things I have ever seen on Slashdot. I would rather see nothing at all than a link on how to build a speaker cabinet. Nerds and powertools do not mix.
Sure, I could just stop viewing Slashdot, but I would miss the thousands of asinine comments that make me feel like a normal person. Instead, I have chosen to join the ranks of people who actually believe that anyone else on the Internet gives a damn what they think.
Ladies and Gentlemen, Slashdot has reached a new low (and not just because I've finally posted a comment).
Why is it that almost every article I read has 70-bazillion (rough estimate) comments complaining that the article isn't news? What's the point of that? You're obviously not accomplishing anything by posting, because you'll inevitably come back the next day and find 10 more articles that you don't consider news.
Ooooh, for a moment when they said "Build your own subwoofer," I thought they meant out of spare parts at home.
Actually, he meant, out of parts taken from another subwoofer...
See what happens when you have old episodes of MacGyver on tape?
MacGyver could break out of a turkish prison with a straw and a toothpick...
I think I'll keep my JBL SB-5. I can deliver all those sounds that you can't hear but feel. :) A cool device with 4 speakers inside where they are facing eachother 2 by 2 in 3 chambers. PDF tech doc.
I have built subs for my car, but the only problems is that even when you get the sizes calculations right, it just doesn't always sound right. So this time I have settled with a pre-built one, the advantage here was the I tried a few in my car to find the one that sounded right in my car.
my sig
about 300 people out of my 1400 member highschool could have gotten alot out of this article..or rather the comments. they all seem to be of the mind that you can throw a pair of 15" subs in a plywood box and throw it in the back of your car, and then they wonder why it sounds like an amplified fart when the bass hits.
If you can't see the value in jet powered ants you should turn in your nerd card. - Dunbal (464142)
In the 20 or so years that i've been listening to them, subs which use relatively small, high-excursion drivers in a sealed enclosure have been the best, especially for percussion. They need more power, but it's worth it.
Ported subs just don't seem to have the *punch*, and it's tiring to listen to music which has a lot of info near the resonant freq of the port.
What was it the last line on their website said?
Something about it controlling his pacemaker and a a heavy load on the machine could be fatal to the webmaster?.
I thought so too.. I was expecting a homebrew subwoofer. Like building the subwoofer, not an enclosure. What a rip.
This article should just be deleted now. There's like 10,000 articles all over the place on how to build enclosures. dammit.
"Morons, your train is leaving"
my subs are in the back of my jeep...took the seat out and put in 2 x soundstream spl160 subwoofers running off 2 phoenix gold amps
We played dungeons and dragons for 3 hours.....then i was slain by an elf
I read at +3, so I might not have seen a link to this project. Have no idea if it is any good, but it's certainly cheaper than many other options.
(For those not wishing to slashdot OSDN, it's for gspeaker, a gpl software for determining speaker enclosure sizes)
Jesus was all right but his disciples were thick and ordinary. -John Lennon
The whole project is pointless without knowing what kind of frequency response this enclosure will supply. It will most likely be very loose bass looking at the basic setup (Not good for sound quality and not good for accuratly reproducing the sounds created by musical instruments). I would be supprised if the whole thing is really cost effective once you add up the price of the parts+time+block amp. Audio equipment is heavily marked up (Around 250%) But this is probably a hard area to beat the price/performance available in the store.
nice looking enclosure. too bad that article has nothing to do with 'building a subwoofer'.
Blue LEDs! Add some of those and you have a geek worthy article.
You're much better off scrapping the whole cone idea and go for a vane/cylinder design. They're much easier to build and often give much better results in a homebrew situation. Try here for some explaination: http://www.mindspring.com/~sdinc/pages/td_new_fam. html
matguy(.com)
I may be opening a social club in the not-so-near future. Among the various plans in getting the place up and running, one of the things I'm concerned about is the audio.
I could go the conventional route and just hang a bunch of Peaveys around the place, but I'm also considering using a big subwoofer under the stage and mid/high speakers on the walls and hung from the ceiling instead. I think this might give better audio quality as well as being easier to do -- not to mention safer, wouldn't want those big speakers falling down.
Does anyone have recommendations on such a setup? Are there any subwoofer speakers available that can handle a large space?
If this is another in a line of "You can, but you should you?" projects, can we get a topic for all of these to go under so I can filter them off the homepage? I'm getting tired of seeing crap like this subwoofer thing, and others like "Here's how I made my kid's jungle gym into a water cooling setup for my Athlon".
"I'm a leaf on the wind. Watch how I soar."
-Hoban Washburn
DEFAULT CATCH
Mod this up. Mod it up to 5. Mod it up to 12. Force everyone on the planet to read it. Ain't it cool!
I hate to poo poo someone, but you poo poo'ed the guy's web site. If you use the Shiva driver he did, and build it like he did, YOU DON'T NEED NO STINKING VARIABLES OR CALCULATIONS!
;-(
Personally, I preferred the NHT, but "whatever floats yer boat", or, in my case, "whatever shakes yer gutters off the house". And yes, it really did.
I agree that this is hardly news, but it's not a bad little diy thing, either.
Mark
Note: I have no affiliation with Acoustic Visions other than a very satisfied customer.
BTW, I am now a nerd for hire. See here if you're looking -- would accept H1B transfer or TN1, preferably in the Dallas area or relo back to Canada.
You could've hired me.
that you're telling me scratching your bum and picking your ear is worth $50 an hour? get real... most of the time you spend not doing anything can be put into something more productive.
Not only this is this article devoid of any useful information for creating an enclosure, but the end product being promoted is probably worth less than the materials used for construction.
Now, if you want to post a link about how to build a ported, tuned, quad-driver system with 4 15" Earthquake Magmas running 4000 watts RMS, THAT'S something I'll read about. Otherwise, wait for some real news before posting.
Yes, and a lot (notice how it is two words) of people (including yourself) at your highschool appear to not know correct English.
If you are going to criticize written English, you better be a whole lot more careful. I took the liberty of using boldface to highlight your errors. "It" refers to a single thing and, thus, cannot be "two words." You should have said "notice how 'a lot' is two words". Note that the word "yourself" is boldfaced. The proper word to use there is "you." Would you say "yourself appear to not know correct English"?
While perhaps syntactically correct, "to not know correct English" is clumsy -- to say the least. You should have ended the sentence with something like "to be incapable of writing English correctly."
Ignoring your poor sentence construction and grammatical mistakes, you reasoning is flawed. You claim that "a lot" of people from his high school write poorly, yet you have only read his writing. You have no way to know how the other students write.
Still feeling cocky?
Your post has to be the worst Slashdot troll ever. Wait, I just did the same thing to you! The difference between you and me and the author of the article and slashdot is that the author and Slashdot have put up.
Me, one day I'll spend $60 for a cheap boomer that comes with it's own amp. I applaud the author for doing better.
DMCA, Hollings, Palladium. What might have sounded like paranoia is now common sense.
Interesting -1 Informative -1 Insightful-1 Troll -1 Flamebait -1 Funny +1 ---- Still totals: -4 eek Slashdot is becoming the equiv of a dumbed down sesame st or what? I built a hack job box like that when i was in H.S. There are thousands of people designing better amatuer boxes. There are tons of info on the net about acoustics,design theory etc. This article is like what you see in fron of AMPM every graveyard. this article.
A Good Troll is better than a Bad Human.
Typical slashdotter: This sucks, the guy should be shot, I'm better than you and everyone else, blah blah blah.
Whatever happened to insiteful comments, gues they take TIME and THOUGHT.
build your own woofer, then put it in your Thunder Table
Your hair look like poop, Bob! - Wanker.
should of read the story first.
Your hair look like poop, Bob! - Wanker.
Gods, I'll bet those side walls flex something awful under full power.
Great, just what the world needs, another annoying contraption to piss off the neighbors. Here's an idea, get these new subwoofer earbuds that I've invented and go blow out your own eardrums.
I don't consider pointing such things out as "poo-pooing" his site. And you can't even "build the unit like he did" (your words) using the information on his page because he didn't even say *anything* about the *tube* he used to create his unit--the single largest component. Nothing about the diameter, thickness, density, length, or even who makes it. This is rather odd given that he went into PLENTY of detail about certain construction details.
Again, the page didn't provide adequate information to build it the unit, much less determine if it was properly designed.
My first speaker was a smack horn. The effiency of a horn is much higher than a closed or ported speaker. I got 104 Db at 1 Watt at 1 meter when a normal speaker only makes about 90 Db. Since Decibel is not linear thats a very big difference. Need i to say that it was well worth the hassle? My old Marantz tuner could play the pants of off any mates systems even if it only had 100 Watt output because of the high efficiency of the speakers.
To build a complicated case is more expensive for a speaker manufacturer than to put in a speaker element that handles higher power. For your amplifier its better to have a nicer load.
HTTP/1.1 400
Now that you've built your own subwoofer, you can cover the higher audio range with a custom made plasma speaker!
"Leave the strategizing to those of us with planet-sized brains." -Tycho
This sub will kick the crap out of any commercial subwoofer less than $1000 (exceptions would be SVS and Hsu Research, but it would still be half the price of the subs from these manufactures that would compete with it). This isn't the car audio crowd who love to pay way too much for crap drivers with pretty logos. This is a Home Theater enthusiast who took the time to do the research and consult those who knew what they were doing.
This guy didn't care to know the theory behind the design, he wanted a good sub on the cheap. The "Patman" referred to is a moderator on Home Theater Forum who really knows his stuff. Patman would have modelled an excellent enclosure design for James and he simply built it. I'm sure Patman could provide me the specifics if I asked, but from looking at the pages I can tell you it will be an EBS allignment tuned to 20hz or lower. Powered with anything over 200W it will be very impressive. Being an EBS allignment using an Adire Shiva driver with ample porting it will also qualify as an audiophile quality sub. Boom box this is not. This is tight accurate bass way above the vast majority of commercial subs.
The fact is most commercial subs have serious design flaws. Their enclosures are too small, they are underported (don't have enough Vp with a passive radiator design) and are tuned too high or have a sealed Q that is too high. You'd also be surprised if you saw the actual quality of most commercial sub drivers. Most of this is a result of size and cost constraints placed on the designers. Keep in mind that a sub that sells at a retailer for $1000 likely cost the manufacture less than $200 to make (add $300 for shipping, infrastructure costs, then double it again for dealer mark up for their infrastructure costs).
$300 spent on a DIY sub will compete with commercial subs at the $1000 or more price point. Spend $700 on a dual Adire Tempest sonosub and 250W per channel pro amp and pretty much nothing commercial under $5000 will be able to compete (output wise, sound quality will depend on what allignment you choose). Get up in the $2000 range and nothing commercial will compete, period. Build a multiple driver (4-12) infinite baffel or dipole sub and you will be in a league of bass never dreamed of from commercial manufactures. In the next 6 months Adire and Stryke will also be releasing some new drivers that will allow DIY subs to widen the price/performance gap with commercial subs even further.
Those saying you can take drivers purchased at Radio Shack or your typical car audio sub are kidding themselves. You'll get a sub that can compete with the cheap commercial stuff, but nothing remotely close to what James has built.
Those suggesting building your own driver are also kidding themselves. The materials needed to make a good quality driver are not something you can just slap together in your garage. If you just wanna have some fun a learn something go for it. If you want to produce a sub you'll actually want to use, get a proven driver (Adire, Stryke, Blueprint, Lambda, Dayton DVC or Titanic, etc). However if you want to get into the design of drivers there are a few driver manufacturing houses that will do a production run on a design with as few as 25 units.
If you want a sub without the compromises made in almost all commercial sub designs take a look at the post that gives links to AVS and Home Theater Forum. Those links will lead you to everything you need to know to build an incredible sub (design software, theory, good drivers and amps, enclosure construction technics, etc).
If you don't have the ability to build your own, SVS or Hsu Research are IMHO the best values out there in commercial subs with the fewest compromises (unless you can afford to start spending well in excess of $2000 without batting an eye).
It's not syntactically correct. "To not know" is a split infinitive. (Remember those?)
Actually, it is correct. In 1998, the influential New Oxford Dictionary of English admitted that "in standard English the principle of allowing split infinitives is broadly accepted as both normal and useful."
Anyone else get a mental picture of Michael J Fox turning up knob after knob, and standing in front of a giant speaker?
:)
*sigh* Maybe some DIY stuff should be left alone
He didn't build the speaker, he built the enclosure for it.
In any case, he used the Shiva II woofer, which I believe is only available without an enclosure, although there are some places making enclosures and selling them with Shiva's already in them. This woofer is around $100 if I remember right, and outperforms many premade commercial products by a longshot. If you know how to use a saw and some basic tools, this woofer is definitely the way to go. I think audioreview.com has some user comments on it, almost all of them positive.
Need Free Juniper/NetScreen Support? JuniperForum
I can't find it anymore, but there was info around on building your own subwoofer from rotary actuator motors, similar to the Mjolnir. Here's a link: http://www.mindspring.com/~sdinc/pages/contra_pu.h tml
They used to have diagrams for which parts you needed, etc. The rub was that a single ~2 cubic foot box with 2 x 12" pistons would equal something like 8 15" standard woofers.
If you want to know all the theory behind a subwoofer (and other enclosures too) you can go at this site. It explains everything (but in french). May be you can try the fish on it it should be ok. Btw if someone wants to translate it in english i'm sure the author will be ok. The author distributes this book freely.
Feh.
An interesting a do-it-yourself project, but can you talk with elephants using it, let alone load it into an Isuzu Trooper?
That seems to have been the going standard for servo-driven loudspeakers for a decade or two.
I had the unique experience of sitting rather directly beside a (somewhat lesser, but similar) dual-cone 15" unit for an evening as I played DJ. I'll spare the details, but do allow me to say that visiting The Throne after returning home that night after having everything homogenized (shaken, not stirred) by the subwoofers was uniquely euphoric experience.
[I'd include more prominent links to Intersonics/Servo-Drive, who still sells these monsters. But their web page is "currently down for reconstruction." Dumb shits. Their old page was at least informative, not to mention existant. groups.google.com for more information, I guess...]
Kid-proof tablet..
next week's article on slow news day
For theirs is the kingdom of Sitonyourasses, and they live only at second hand; so then, should it not bedazzle them when one not so different than they - for, sooth, did he not make a web page of his Big Adventure, to share it with those who but sit and stroketh the keys? - getteth up off of his ass and actually maketh something besides loud whining and stenchful air? To them, he is a wonder and a marvel, a prodigy of individual empowerment, one who has freed himself from the bondage of the Stereo Store, at least in this one small way.
Remember thou who hast a life: to the Slashdottie all is vicarious entertainment. How then should they find it within themselves to resist the lure of a web page, which they can view without discommoding themselves even a jot, about a component to help them feel the diverting special effects in the next Hollywood Smash Hit For The Stupid And Incurably Lifeless? It is almost as good as yet another piece of Star Wars advertisement - your pardon, I meant to say news, of course - the likes of which they cannot stand to pass a day without.
Looketh thou into my mirror; what doth thou see?
You can go to any neighborhood radio shack and get a book on doing all of your stereo building. A quick search through online book catalogues will reveal many books on the subject.
I was always taught that highschool is actually two words, high and school.
He built the speaker enclosure, big deal. And it's not even finished. Any idiot can build a speaker box, but he didn't even build it a specification for appropriate bass tuning. I thought he was building the driver - much more interesting ;-)
Actually, he meant, out of parts taken from another subwoofer...
I see the point. But somehow I get the feeling that if you want a subwoofer, there has to be an easier way....
Do you care about the security of your wireless mouse?
What the fuck's a router in mundane-speak?;)
Is this a sigs-optional kind of place? 'Cause I am totally down with that if you know what I mean.
The guy didn't even put spikes on for feet. I would love to see this perform on a wood floor. It would be all over the place w/ that flat board as the bass.
Surely not slashdot material!!!
next...
Sure, building your own subwoofer might not be news, and it might not be a new idea, but until Slashdot gets a "really cool stuff that doesn't quite qualify as news but it's still for nerds" section, the front page will have to do.
No, this guy's speakers aren't that great.
There are some good points, however. He's doing nothing of note constructionwise, but the larger choice of the sonotube has significant advantages and disadvantages. Big plus: tube shape means walls CANNOT flex from pressure. That allows for potentially thunderous reproduction of the sound coming out, without overhang or weakening of the fundamental. Big minus: the sound coming out is strongly colored by the inside of the enclosure being the second worst possible shape in the universe- worst is a sphere. Testing has shown that these shapes are the best possible for the outside of an enclosure, but the worst for the inside.
What I've found works best for really serious bass is multiple drivers of gradiated sizes. My mains are running 6.5/8/10/12 drivers series-parallel like a Marshall cab- wattage is comparable to four of the weakest speaker (6.5) series-parallel, because that's the one that'd blow first. I have a narrow but absurdly deep cabinet, internal walls, bottom two sections ported and the top two open-backed. I had acoustic foam in there but found that it sounded better in the mids to leave it totally open, since all the resonance and reverberation goes straight out the back. The bottom, with the 10 and 12, has two good-sized ports, but since the box is so big (and it's running acoustic suspension drivers, too) the port only extends the lows further- it is not tuned high enough to make 'one note bass', it's reinforcing the really extreme lows.
If you want a REAL geek audio project, make some supertweeters like I did. Small piezo drivers (I'm using some fairly rigid and tough-to-solder-to ones I got in bulk), mount them on something solid while leaving the middle free to flex (rigid mounting like superglue, not a soft gasket), and then take some envelopes with that clear cellophane stuff that crackles easily if you rumple it. Cut out rectangular pieces big enough that you can make an 'M'- you're going to be making a degradation of the Lineaum cylindrical driver. That requires a piece to translate piezo flex into true linear motion- as shown in the *spit* patent- this skips the bridge piece and applies flexing-disc vibration directly to the leaves of the driver. In doing so it fails to be a proper line source- but the weight of the moving mass is that much less!
Take two 'leaves' and superglue them together at the base. You can trim them a bit so there's a slight ) shape to the part that'll be glued to the piezo. Take a bit of acoustic foam, superglue the outside of the sandwich of cellophane on one side to it, attach it to the speaker to the side of the piezo (which you should have wired up already). Then do the same to the other side- you want a 'm', seen from the top, with the middle bit resting directly on the piezo. The 'm' shouldn't be too tall, but it does have to form full half-cylinders- it shouldn't be flat. Finally, if it's all good, put a dot of superglue on the middle of the piezo, and allow the center of the 'm' to be attached permanently.
How it works: pressure from the piezo displaces the cellophane. Since it's two loose semicylinders, it flexes, choosing to compress together at first rather than shift the whole structure outwards. Surprise! The semicylinders form an exponential horn- and you've just compressed the throat, forcing air out! In addition, the wave will travel outward from the center, until it dissipates by air resistance and eventually the acoustic foam mounting at the far end. This tweeter goes up forever, way beyond CD capabilities, very cleanly, and it also has phenomenal dispersion characteristics- very wide soundfield, virtually no beaming. The difference is not subtle.
In a perfect world, lots of people could work with this technique and develop it as free software is developed. I've seen the patents on the _refined_ version of this- involving a bridge piece between the (not truly linear) driver and the base of the cylinders- and until the patents expire, this is officially proprietary.
I am sure that will dissuade MANY slashdotters from getting cellophane, piezos and superglue, and building their own supertweeters. Don't you people know developing on ideas someone else had is wrong? Remember, whoever-it-was who said, "If I have failed to see farther, it is because I wasn't allowed to stand on anybody's shoulders, so there" ;)
Why have I taken so much effort to communicate this technique? Because I'm a speaker designer myself. I have numerous ideas that are in fact mine, and hybrids of those with things like the Linaeum cylindrical driver, some of which are just terrific. And I'm very annoyed by a reality in which I cannot function as a simple artisan and idea-haver, without patent-wrestling with corporations- and in which I can't even go ahead with my own stuff, as corporations will take anything that's really good, and patent it since I won't, possibly even stopping me from using something I've invented. It makes you want to hide and never build anything.
There's nothing to do but go ahead anyway, but understand that my 'outing' of a homebrew way to do a degraded form of the Lineaum piezo driver patent is a combination of 'power to the people' and simple bitterness. What would have happened if the person to make the first cone driver had locked it up with patents, filed extensions, retained control of it to the present day? There'd be virtually no speakers, is what.
I feel the ideas that MOST deserve patent protection are the ones that most harm the scientific environment through their being guarded by lawyers. 'swinging sideways on a swing' patents are harmless. The ones that are REALLY GOOD are the ones that NEED to disseminate out into society.
sonosubs are very popular in DIY home-theater circles. I built one myself and it's not that difficult at all. Sounds awesome and easily rivals subs that are over $2k +
But it's not even a particularly new/clever/well presented/information rich example of a sub woofer either... the same type of sub design has been shown many, many times before... so why was this one posted on Slashdot?
I spent WAY to many hours reading up on homemade subwoofer construction for my home A/V system, and settled on one somewhat like the one in the article. It took me and my Dad about 8-10 hours to build and cost around $250 US. With a cheap 150 watt Parasound it blows the doors off the house when cranked up (which I don't do often since I already have tinitus from my punk-rawk days) but can blend nicely for really smooth bass when listening to music.
See it here:
http://wisdomtools.com/~brbothwe/shivasub/
If you have the excellent BassBox Pro 6, here is the BB6 data file:
shivasub.bb6
This design (like most sonotube subs) is ported. Even smoother subs (for high-end audio) can be made sealed.
The following site has probably already been posted, but if not check it out:
http://www.diysubwoofers.org
yeah the woodwright shop is a much better and more interesting show because he likes to talk about how the various tools were invented, their history and all. besides, you can't say that a guy who makes his own tools isn't cool.
Large print giveth, and the small print taketh away
http://www.txraves.org/~magnetik/diy/Page.html you can see how you cut holes with the router with a jig in one of the shots... Julian Brock
YOU TOO CAN MAKE BIG MONEY IN THE EXCITING FIELD OF PAPER SHUFFLING!
Mr. Smith of Muddle, Mass. says: "Before I took this course I used to be
a lowly bit twiddler. Now with what I learned at MIT Tech I feel really
important and can obfuscate and confuse with the best."
Mr. Watkins had this to say: "Ten short days ago all I could look forward
to was a dead-end job as a engineer. Now I have a promising future and
make really big Zorkmids."
MIT Tech can't promise these fantastic results to everyone, but when
you earn your MDL degree from MIT Tech your future will be brighter.
SEND FOR OUR FREE BROCHURE TODAY!
- this post brought to you by the Automated Last Post Generator...
Just because they are called 'forbidden' transitions does not mean that they
are forbidden. They are less allowed than allowed transitions, if you see
what I mean.
-- From a Part 2 Quantum Mechanics lecture.
- this post brought to you by the Automated Last Post Generator...