Glass Loudspeakers

I recently came across an article in the January edition of Popular Science about these:

Greensound Technology | Home

Glass to me would seem to be inefficient and prone to resonance, and I'm having trouble seeing how the motor imparts movement - does it propagate upwards through the glass panels, or do the curved panels at the base actually provide horizontal pistonic movement?

They're $8,000 a set - you could pay a lot more for boutique stuff, but it's still up there. I do thing they're rather pretty though. Would also seem to be a very challenging DIY - machining the glass for one thing.

Anyway, I just wanted to post this to see if anyone knew anything about the technology/mechanics, and if you've seen anything like this before; it's new to me.

Cheers
 
Rodeodave -

Yes - the frequency range is limited, but Crystal Cable is just that - cables, not loudspeakers. And the Waterfall Audio speakers use conventional cones with glass cabinets.

With Greensound the actual sound generating membrane/diaphragm is glass - if you notice there really is no cabinet - these are like open baffle or planars/electrostats.

So, I was just soliciting thoughts on what the motor structure might be, and how glass panes could possibly make a good speaker diaphragm.
 
Those, AFAIK, are exciters for NXT-style DMS loudspeakers. A very plausible way of turning a sheet of anything into a loudspeaker (of sorts)

dave

Then the question becomes how good would the speaker be, with a (big) sheet of glass as the diaphragm, and what kind of amplifier power would it take to drive it.

It would also depend, of course, on the quality of the exciter.
 
DML

I recently came across an article in the January edition of Popular Science about these:

Greensound Technology | Home

Glass to me would seem to be inefficient and prone to resonance, and I'm having trouble seeing how the motor imparts movement - does it propagate upwards through the glass panels, or do the curved panels at the base actually provide horizontal pistonic movement?

They're $8,000 a set - you could pay a lot more for boutique stuff, but it's still up there. I do thing they're rather pretty though. Would also seem to be a very challenging DIY - machining the glass for one thing.

Anyway, I just wanted to post this to see if anyone knew anything about the technology/mechanics, and if you've seen anything like this before; it's new to me.

Cheers

Distributed Mode Loudspeaker

Conventional loudspeakers employ a reciprocating diaphragm of relatively small area, operated over relatively large excursions, to achieve the required volume displacement of the surrounding air. Alternatively, bending waves, of very small amplitude, are generated within a glass panel of much larger area, to produce the same output. To suppress inherent panel resonances and mitigate the acoustic (and mechanical) fragility of glass, panels are fabricated from two thin glass sheets laminated to a PVB (polyvinyl butyral) core. Unlike the up-front acoustic image of conventional loudspeakers, that of large panel speakers lies far behind them.

Regards,

WHG
 
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I forgot:

If I remember, once Moray James has been writing very good posts about his experiments on DML. He was using very thin glass, and said the result was amazing but never went commercial.

I think it's buried somewhere in the Ariel thread, maybe in the early pages...but i'm not sure.

good luck.
 
Hello,

Some examples of laminated glass cabinets here :

and their "white paper" here.

I think it's not totally honest because they cheat on the range
of the CSD plots when it's their glass product, anyway can be read.

In case you would order, just prepare 556.000 $.

Diamond cabinets ?

Sorry - again we're not talking about the cabinets - we're talking about the diaphragms.
 
Distributed Mode Loudspeaker

Conventional loudspeakers employ a reciprocating diaphragm of relatively small area, operated over relatively large excursions, to achieve the required volume displacement of the surrounding air. Alternatively, bending waves, of very small amplitude, are generated within a glass panel of much larger area, to produce the same output. To suppress inherent panel resonances and mitigate the acoustic (and mechanical) fragility of glass, panels are fabricated from two thin glass sheets laminated to a PVB (polyvinyl butyral) core. Unlike the up-front acoustic image of conventional loudspeakers, that of large panel speakers lies far behind them.

Regards,

WHG

I forgot to mention that the glass is tempered - layered/laminated - that makes a big difference in it's characterisitcs.

So it looks like it generates bending waves - like - what - the Mangers?
 

gstspeakers

Member
2010-12-23 11:07 pm
GST Speakers

Hi all,

We are excited to see that you are interested in Greensound Technology. After reading over some of your questions and comments, we would like to take the opportunity to provide you with some information.

Greensound Technology provides high-end speakers that produce sound though glass. With multiple designs, price points, and additional features, our products are available for both commercial applications and multiple sectors of the consumer market.

Of course, our approach to auditory technology is proprietary. We can only tell you that superior sound quality is achieved though the precise engineering and configuration of each component.

If you would like to experience the sound of each speaker set, come out and see us at the CES 2011 1/4/2010 - 1/9/2010.

Thank you,

Joey Landeis
Director of Marketing
Greensound Technology
Email: [email protected]
Website: Greensound Technology | Home
 
I concur with whgieger. Definitely some kind of DML using a glass substrate.

Probably actuated by something like this:

FeONIC: Invisible Speakers, In Wall Speakers, Public Address, Marine Speakers, Sound Zones

NXT has also published an AES paper on laminated glass substrate flat panel speakers.

A Novel Glass Laminated Structure for Flat Panel Loudspeakers
Authors: Harris, Neil; Mal, Olivier; Novotny, Marek; Verbeeren, Bart
Affiliations: New Transducers Ltd. (NXT);AGC Flat Glass Europe
AES Convention:124 (May 2008) Paper Number:7343


Very interesting technology, with some intriguing possibilities.
 

Mapper

Member
2009-09-11 10:00 am
Hi Adason

I'm the FeONIC web developer. I can't see those figures you've described. Certainly not for their main F1.3 drive.

Figures from the downloadable PDF spec sheet for glass.

Sensitivity: 69dBA @ 1m ( one drive can turn an entire wall into a speaker so not sure how relevant sensitivity is).
Typical Bandwidth: 80Hz-20,000Hz
Sound Pressure Level3: Peak 98dBA (SPL 95dBA) @ 1kHz 1m

I've noticed a discrepancy - the site states Typical bandwidth 63Hz-20000Hz and the spec sheet has 80Hz. I'll get that sorted after the holidays.

but nowhere is 200-10kHz mentioned that I can see. Can you point it out?

But agree that FeONIC drives aren't suitable/intended for 'perfect' hi-fi (however you care to define that and much of that depends on the depth of your pockets). One Hi-Fi shop I've seen them demo'ed in (selling only seriously expensive kit and located halfway between Eton school and Windsor Castle so it is very posh) will sell £30K to £100K hi-fi setups to the super rich (footballers - russian gangsters etc) and put FeONIC drives throughout the rest of the house (kitchen, bathrooms, sauna (drive is outside so never gets wet), halls, bedrooms etc. Good for a home cinema setup too. Mainly useful if you want 'good' sound but don't want wires and boxes causing clutter.

As I'm no audiophile that's the only way I can describe the sound quality. Good enough for the super rich with more money than they know what to do with but generally for certain applications.

Hope that helps

Stuart
 

adason

Member
Paid Member
2004-11-10 8:31 pm
Maryland
I was referring to this fr response...
 

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