"Invisible" Speakers

Maurice Boughton sent us a link to an interesting bit about speakers that you can mount to your wall to let it resonate as a speaker. You read more. They're only like $60 so it might be worth it, although I'm curious how they sound. Oh, and as for the 6 billion of you who emailed me to wish me birthday greetings, thanks, now stop!

Comments

Re:OLD technology.. Audiophiles.

[Rob Parkhill]

Most audiophiles are over 30 and can't hear the full range that their speakers are capable of reproducing anyhow.

Of course, there are exceptions to the rule. Like a prof I had at the UofC. Back in the early days of CD's, he could actually hear the frequency modulations in cheaper players. To fix it, he would encase the quartz crystal in many pounds of lead (I think) and bee's wax. He pretty much built his own CD players and converted many of his audiophile friends to them, at a time when audiophiles just snickered at CD players for their lack of decent sound.

For those from the UofC, yes, I'm talking about Chris "Mr. Tangent" Walpole.

OLD technology

[tgd]

21st century? What a joke. How come we keep getting essentially nothing but ads for lousy tech on here so often?

I've heard units like these before and they sound like crap. Beyond the inherant fact that wallboard doesn't conduct sound that well and tends to be a very dampening surface, you'd have problems with resonance in the airspace behind the wallboard, problems with the point that the wallboard touches the joists in the walls.

The only thing this sort of technology has ever been even remotely good at is providing a bit of rumble to people in their cars -- and even then, no serious auto audiophile would come near them.

A company called Aura makes/made them for cars. Bass-only because they're at least smart enough not to claim that heavy surfaces like that can conduct and transmit cleanly the higher frequencies into the air.

Hrm. Not new, but now cheap...

[Mickey Jameson]

I first heard about these 5 or 6 years ago back in the days of living with roommates. One of the two was a tremendous bullshitter and managed to acquire a demo of those type of speakers. The only reason he wanted them was to piss off the upstairs neighbor because he was a dick. Apparently they worked too well, because 7 days later, we got an eviction notice.
But anyway, they cost a pretty penny back then, but now only $60. Definitely worth looking into now.

Re:Their claims don't make sense.

[The Mayor]

Well, this speaker advertisement is full of feces. However, you are wrong when you say that sound pressure levels == volume.

Check out: http://newport.pmel.noaa.gov/whales/acoustics.html #levels

Sound intensity levels == volume, not sound pressure. If a transducer is a point source (conventional speakers simulate point sources), then sound intensity is roughly equivalent to sound pressure. However, with complex combinations of tranducers, you can have high sound intensity levels with low sound pressure levels (and vice-versa). We measure sound pressure levels only because it is easy to measure (simply measure pressure, and compare it to some reference). I believe that sound intensity levels require directional arrays of tranducers to measure, and are typically only measured when environmental regulations require them.

If you remain unconvinced, go check out your local environmental laws regarding sound pollution. They have separate requirements for sound pressure levels and sound intensity levels.

Who's making up false claims? Let's test!!

[CodeShark]

The web site source has spoken. Accused me of making up false facts. I'm S-O-O-O surprised. Invisible1, you've cut me to the quick... I must NOT have done those things I said I did... that's it -- it was all a dream -- a hallucination, yeah, that's it... [Forgive the sarcasm. The accusation of dishonesty pissed me off royally.]

I'll admit a bias here. I've never heard an in-wall speaker or system that matched the quality of a similarly priced free-standing speaker. So I would not be at all surprised if your Invisible Stereo speakers sound MUCH better than other in-wall designs. But I'd be very surprised if any in wall system is cost competitive with well-designed free standing speakers. Now then, because of the accusation of dishonesty, I'm going to do my best to shred virtually every iota of Invisible1's post. Mostly from the standpoint of price.

1. A 10 room Invisible Stereo system costs $3990.00 ($399.00 per Room, installed w/volume control) Two questions: (A)why in the h--- would I want to install speaker systems in ten rooms? What if I move to a new house? and (B)Assuming ten rooms, how many different audio feeds are we talking here? One high fidelity system? One per room? How do you prevent crosstalk, etc.?
2. ...
3. and a 20 transducer Home Theater is $1995,installed. Although I'm not in a position to spend the time or money right now to do so, if I was, I'd wager that I could put together a similar sounding system for around $1995, but I'd also buy myself a new DVD player, audio CD, graphic EQ, and speakers (surround) -- everything except for the amplifier. And STILL be able to move my system any time I wanted.
4. Most In-wall speakers that are worth considering START at $400.00 UNINSTALLED, (see my inital comment about bias)and any good matched SS speakers including Rear Chan. Dipole/Tripole radiator designs will average $600-800 ea. I assume by "matched", you mean "pair". Your costs are about right. But if I'm building a pair from transducers on up? The finest free standing speakers I've ever personally heard were built [and are owned by an true audiophile friend] -- for a net component cost of around $700. About $200 more for the surround speakers, BTW] Returning to the idea of portability -- he's moved seven times since, and taken the speakers with him.
5. I can attenuate/accentuate the frequency response by varying the thickness of the Mounting board and just send the Full range signal to them.I'll admit being confused by the mounting part of your comment. And I can see how different mounting boards would provide a smooth response. But does that mean I have (1) a wall made up of a bunch of different types of boards, or (2) drivers mounted to boards mounted to the wall? Option 1 isn't practical as far as I can see, and option 2 (which takes care of the portability problem -- unscrew the boards and take the drivers with you) doesn't address the fact that different frequency sounds would have to travel through two layers of wallboard, etc. A clarification here would be honestly appreciated.
6. Backing up a little, you said that "and I hardly EVER use crossovers" The best speakers I ever designed (4 way, bass reflex, BTW) only REQUIRED one per cabinet. But it wasn't an inexpensive part of the speakers, even at that. (Note, I used two per cabinet in the final design. It sounded better.) Good crossovers aren't cheap. Especially -- which will bring me to my final point -- if the crossovers and drivers are to have adequate power handling capability.
7. The IS transducers are rated at 50 Watts RMS continuous Music. At what efficiency? This is a key question: my own speakers are rated at about about 200 watts RMS per cabinet, with mid-range efficiency (92-93 db/w/m) I don't use all of that capacity most of the time, but when I need it (usually a movie soundtrack or symphony -- some Dregs, Yes, Styx, Journey, and other '70's and '80's rock) If the end Invisible Stereo product isn't at least as capable -- unless I'm missing something here, and I could be -- how in the hell am I supposed to enjoy the full dynamic range of a DVD movie or favorite CD-ROM?

I'll put up or shut up now. Within the next half hour, you should be receiving an e-mail with info on where I live -- you let me know where there is a system nearby, and I'll give them a listen -- and with Rob's permission, publish my honest review here on /. [Note: I don't work for any stereo companies, so this will be an unbiased, listening test only.]

You got game? I got ears. Let's put these to the test.

Don't waste your time or money on these.

[CodeShark]

[Note: in "audio speak" a driver is an individual sound source -- often a speaker cabinet will have three "drivers" which show on the front - a large (bass), medium (midrange), and small (high frequency) 'driver']

I don't claim to be an audiophile, but I've got both the math background and good enough ears to know when the math works and when it "just ain't so." This can happen in one of two ways:

1. there's no way a design can produce a high quality sound, or
2. spending more money won't dramatically improve the sound.

From this background, let me tell you that as proposed on this web-site, it's not only unlikely but damn near if not impossible to design a worthwhile sound system using these drivers. Here's why:

• Multiple transducers, are required for even moderate quality sound. With more than one of these so called "invisible speakers", there is no vibrational isolation between the low (bass note) frequencies and the high frequencies. Which means that even if wall board, plywood, etc. could accurately respond to the individual driver's frequencies, the vibrations from the low frequency drivers would muddle up the other frequencies.
• (Quoting)...speakers by design focus their energies on creating high Sound Pressure Levels within a room to provide "presence"... This might be true for stadiums, theaters, etc. (large areas) but not the typical home system. he main requirement for good sound in a home setting is the ability to tune the system to match the acoustics of the room -- thus cancelling out the effects of standing waves, absorption of sound by furnishings, etc.
• ...audio purists seek speakers with flat frequency response, non-directionality, and and efficient db-to-watt level. Wrong again. Audio purists are not THAT interested in efficiency, because most (but not all) efficient drivers have very uneven frequency response.
• Different size drivers are better for different frequencies. This means that there is
• no "one size fits all driver" that can match multiple drivers through all pitch ranges. Even the high dollar audiofile "flat" speakers usually have a cone-driven sub-woofer because the "flat" speakers can't move enough low-frequency air.
• I'd rant for a while longer but here's a more practical way to throw this idea away -- what happens if for some reason you decide to move your home theater to erk -- a different wall, or a different room?

• Note to Rob: rather than spending any $$ on these, buy yourself a 10 band stereo equalizer. It'll save you a ton of money and make any stereo speaker or system you'll ever buy better because with it and a little patience you can tune your system to the room .

Wall speakers

[Jim Hurlburt]

I don't think I would like to live next door to the clown with these things in his walls. Can you imagine living in an apartment complex with people on either side of you playing different stations/cds. Seems like it would be worse than someone carrying a boom box down the street.

I'm bloody skeptical

[Fish Man]

Having dabbled in speaker cabinet design, and designed a few PA systems, been a sound guy for bands, etc., I have a few serious reservations about how well these things would work.

The biggest ones:

1) Aren't the characteristics of the sound going to have huge dependencies on the construction of the walls, the size, stud spacing, wallboard thickness etc. If the wallboard is a little loose wouldn't it "buzz" against the studs? Would pictures vibrate? Wouldn't things like stud spacing, wallboard thickness, wood hardness (of the studs) and other factors affect the flatness of the frequency response. What about metal studs? What about lath and plaster walls vs. paneling vs. sheetrock etc. ...infinitely more construction based variables of course.

2) There are several evidences in the advertising copy of junk science and BS double-talk. For example, the site claims that this technology eliminates standing waves.

Standing waves are (almost) 100% a function of room geometry (primarily dimensions of the room vs. multiples of wavelengths, absorbancies of various surfaces in the room also come into play) and (almost) 0% a function of speaker design. This claim (and some others on the site) dump its credibility into the toilet IMHO.

Bottom line, IMHO this system is likely to not sound very good at all in the majority of installations.

This is a bout as ridiculous as anything I've seen

[aderusha]

First: boy does this site suck. Looks like a retarded 4 year old chimp on methamphetamines designeded this in the midst of a particularly violent flashback. In notepad.

Second: The premise is silly. All of a sudden, they are able to turn my house into a finely tuned resonating cavity for the entire ferquency range? You must be kidding. Sheet rock doesn't resonate for just about anything. Well designed and well constructed speakers are expensive cause... they're well designed and well constructed.

These thing an an affront to my own intelligence.

Somebody help them with their web page

[B.W. Hogg]

Most personal home pages I've seen are better than that. That's pretty cheezy. I wouldn't buy anything from anyone with a page that cheezy.