PIEZO NXT type panel

[LineArray]

I think in this Article there is a more beautiful picture of the device:


http://www.dl0sn.de/informations/rep...adiomuseum.pdf

[UKPD]

Hi There,

I'ts my first post in this thread but I've been following it with great interest.
Have you come across Aerogels or as it is sometimes called Frozen Smoke?
Seems like ideal material for NXT panels with its strength to mass ratio.

Peter.

[LineArray]

Hello Peter,

i heard about it but did not have it in the materials list
up to now.

I think some loudspeaker manufacturers use Aerogel (Focal e.g.)
to build sandwich laminates for conventional
drivers.

Would an aerogel of thickness from 0.5 to 5 mm be airtight ?

If not, we would possibly need a coating for low frequencies, where
tightness of the panel is an issue.

Then the low mass advantage compared to other materials would
decrease. Also damping is an issue.

Styrofoam e.g. has also low mass and high stiffness and is still
airtight when cut to thin panels. But styrofoam rings like a bell
and needs a damping coat IMO.

Are you experienced with aerogels ?

en:
Aerogel - Wikipedia, the free encyclopedia

ge:
Aerogel – Wikipedia


Kind regards

[matejS]

Hi,

what material do you recommend? Gatorfoam? Any better?
I guess Kapa is not good... what about Dibond (0.3mm alu with foam inside)?
Any other idea?

Thanks,
Matej

[el`Ol]

Originally Posted by matejS

I guess Kapa is not good...
Matej

Why is Kapa not good?
Probably the Kapa bloc with resin coating is not so far away from the Gatorfoam. Pursonic is also Polyurethane.
purSonic flat panel loudspeakers - invisible sound systems

[theAnonymous1]

Originally Posted by LineArray

Hello Peter,

i heard about it but did not have it in the materials list
up to now.

I think some loudspeaker manufacturers use Aerogel (Focal e.g.)
to build sandwich laminates for conventional
drivers.

Would an aerogel of thickness from 0.5 to 5 mm be airtight ?

If not, we would possibly need a coating for low frequencies, where
tightness of the panel is an issue.

Then the low mass advantage compared to other materials would
decrease. Also damping is an issue.

Styrofoam e.g. has also low mass and high stiffness and is still
airtight when cut to thin panels. But styrofoam rings like a bell
and needs a damping coat IMO.

Are you experienced with aerogels ?

en:
Aerogel - Wikipedia, the free encyclopedia

ge:
Aerogel – Wikipedia


Kind regards

Aerogels are insanely expensive.

[tiki]

...which we used, could be destroyed by water instantly. It was easy to grind between fingers.

[croat47]

Yeah...the capillary size in the inter-connected pore structure is so small that the water's surface tension in the small capillary crushes the glass web. Go ahead, put a piece on your tongue. If you pull it off, the surface of your tongue will come with it. (No...I did not experience that myself.) But, that is the stuff I have made/worked with before.

When people say "aerogels" I wonder what they really mean...just like "nanotechnology" that actually works on a "micro" scale.

[UKPD]

The idea was to use it in a sandwich type of structure in between two skins. Does anybody know how resonant Aerogel is? I only saw it in a granular form.

[mondogenerator]

Originally Posted by croat47

When people say "aerogels" I wonder what they really mean...just like "nanotechnology" that actually works on a "micro" scale.

yes i know the feeling...to my knowledge neither styrofoam, polyfoam or any other readily available foam is ACTUALLY an aerogel...i believe they are by themselves extremely delicate , usually best utilised within a composite consisting of fibres(maybe Carbon fibre? Aramid? Both?) or perhaps a honeycombed Al structure, filled with it? i duno this is all way to conceptual. maybe we should all try and fashion a diamond monocoque tweeter diaphram too........or maybe if the sky wasnt the limit we could just limit it to silicon carbide....LOL

I believe they were originally developed for their heat insulating properties, and are still very hard to obtain, hence mucho expensivo