Turn Your Head Into Speakers

Roland Piquepaille writes "A small company based in Iowa has developed products made with a "smart" metal that can turn your walls or your head into speakers. "Last August, Etrema -- an innovative technology firm nestled in the cornfields of Ames, Iowa -- started selling those chrome discs for $1,500 a pair. Called Whispering Windows, they can turn any wall, window, or drab conference table into a speaker." The author tried the technology, and even if she needed a full bottle of Tylenol after usage, said "it's not every day that your head serves as a piece of stereo equipment." This overview tells you more about this "magic" metal, the Terfenol, which is a combination of terbium and dysprosium. The article also says that we can soon expect pirated versions of Terfenol coming from China."

Comments

Re:Been done before?

[PaintyThePirate]

Acually, the SoundBug uses Terfenol.

Etrema is now trying to secure a major retailer to sell a $300 portable version called the Presenter, aimed at business travelers, that can plug into laptops and give any room a top-quality sound system for presentations. A toy version, the Soundbug, is available for $20 from Amazon and OfficeDepot.com. Despite the poorer sound quality, teenage boys seem to like it.

Re:ThinkGeek

[dirkdidit]

Take it from somebody who shelled out the $30 for one of those things, they suck. Not just a little bit, but a lot. The thing rarely worked on the surfaces I'd put it on and on the surfaces it did work on, it still sounded like a dying cat. Not to mention that it is about the flimsiest thing I've ever used. It broke after only 2 weeks, though I can honestly say I wasn't heart broken.

Sure the SoundBug is a cool gadget but I strongly doubt it's even close to the product quality of the $300 this company is selling.

Been done before...

[ThogScully]

I don't know what particular metals are used in Bass Shakers, but I don't really care. They aren't Sound Bugs like everyone else has posted a link to and they work exceptionally well to create a speaker out of whatever you screw them into: car chassis, couch, wall, whatever.

Specifically, they are intended for bass reproduction, but that's the only frequency domain where the material of the cone isn't having a dramatic effect on the sound quality, so I wouldn't necessarily want full range production from whatever random materials I can find.
-N

Walls as speakers in the military

[MemoryAid]

The military has transducers used on walls to prevent people from listening in on classified conversations. I've seen them installed in aircraft carrier ready rooms, where flight briefs take place. One can put an ear to the outside of the wall to try to listen, but can only hear the (usually lame) music in the wall.

This system is not designed as a speaker, per se, but it is audible from near the wall. I have no idea what flavor of unobtanium is used for these, but I suspect they probably cost at least $1500, based on the military's track record.

Re:Similar to hippy technology

[wjsteele]

Wow! I forgot about that thing. I had one. It was called the Bone Phone. It was a soft cloth covered device, about 18" long, 3" wide and 1" thick. You simply layed it around the back of your neck, with the two ends over your collar bones. The controls were at one end and batteries at the other. It did have speakers, but it didn't vibrate your collar bones... the speakers were positioned above the unit, right under your ears so you could hear it even with the volumn turned down low. This made it hard for others to hear.

It was a cool radio, but the walkman idea was better, because you couldn't jog with the Bone Phone on, it would too easily fall off.

Ah... thanks for the memories.

Bill

Rare Earth Elements

[Detritus]

The Industrial Physicist has an interesting article (PDF file) on rare earth elements that mentions terbium and dysprosium. According to the article, 3.6 kg of dysprosium will set you back about $50,000 US.

Naval Ordinance Lab

[gessel]

The ~NOLs are inventions of the Naval Ordinance Lab, curiously located out there in the corn fields; famously NiTiNOL and TerFeNOL, not exactly the the most overwhelmingly original names, they do sound techy.

The "latest" material, terfenol, exploits the giant magnetostrictive effect, which sounds even more brand new, but it isn't, having been discovered in the 1840s.

The high strain versions of this (and the thermally actuated "shape memory alloys") were developed in the 1940s for use in high powered sonar. They are generally used as replacements for voice coils and for the same reason. If you want to actuate your domestic structure, you can use a big one and keep it cool with LN2.

These materials are far too old to be covered by existing patents, so they're fabricated all over the world. Indeed, chinese manufacturers are in production.