PIEZO NXT type panel

[jzagaja]

NXT writes they have tried variable thickness BMR and DML that gives better high frequency performance for a given f0. Also profile compress instead of machining maintains a uniform mass-per-unit-area. I was told NXT designer simulates piezo driven panels as well.

[Ziggy]

Great to see you guys are getting in to the physics and technicalities of this subject/technology.

Wish I could understand it all......but I'm getting the drift.
Keep it up fellows!

[el`Ol]

I just got my 50x100 cm Balsa board (3x1mm). http://www.balsabar-shop.de/
Compared to the Rohacell board with about the same mass per surface it has better transparency (comparable with a conventional speaker) and sounds much more "alive". Neutrality is also better. In fact I could live with it very well if there were not these nasty resonances.
The choice between more or less damped material seems to be like the choice between plague and cholera.

In an old thread there was mentioned a DML design software from NXT (unfortunately with dongle and I don´t know the price). Does anybody know whether there is an alternativ now?

[båndsei]

I have been using polyueretane "foam" from a spraycan to make some panels for my planar speaker. I was wondering if it could be used to make your own "panels",may be with a piece of wood to atack the exiter to,and some paper as surface. The polyeuretane expands after a while , so you have to make a fixture.
Hope you understand it.
[IMG][/IMG]

[MrMulugulu]

Hello from germany,

15 sites in English i too much for me

so i will build a speaker for my PC on the wall.


what is the best wood and size also?




@lineArray


würde dich gerne mal per email um deine erfahrungen bitten, nur leider ist das mein erste rpost und kann dir somit nicht schreiben

[jzagaja]

Patents confirms that Ciresa (Operasonore) uses bimorph disc only in a whole audio range. I've got bimorphs from APC International, Ltd., impedance 1,2kOhm, capacitance 150nF, Fs=65Hz. Plays even loud glued to the wooden desk.

[pol_bct]

Hello All

> Patents confirms that Ciresa (Operasonore) uses bimorph disc only in a whole audio range.

it seems that they only go down to 200Hz
the cheapo DAEX25 goes to 60Hz when properly used
but with reduced output

POL

[jzagaja]

Panels go down below 100Hz with a volume velocity I suppose. Disc bender seems to have higher fundamental resonance. Anyone already used Chladni patterns for n=0,1,2,3... modes to find excitation area? This is a nice violin makers technique and could work as well as FEM simulations. Impedance and capacitance for piezo is high, resulting efficiency rather low. Time to wind tranny.

[pol_bct]

Hi all,

> It all makes sense now when you realise that the PODIUM speakers mount their drivers down the centre line of the panel width. Also noticeable from the photos on 6 moons , and as mentioned before, no one driver is positioned at the EXACT CENTRE of the panel - important?....yes, I think so.

Ziggy , I dont know if you are still on this job
but the picture shows clearly that transducers are exactly on the center line. I have done some tests, only this central position give the maximum bass extension. And if the motors were aligned on the short axe of panel, instead of the long one, this would extend again bass response. (plain 1/4 wave excitation)

POL

[pol_bct]

>> Originally posted by WrineX
> then they sound incredible and the next day they suck. day after they sound superb again.

Hello
yes, this is true, because the sound relie only on the quality and state of the material used for the panel. It may change greatly with hygrometric and electrostatic state of this membrane. I use a stereo set of 2x8 DAEX25 on a 1m panel (inline source), sound can goes up and down from incredible to awfull in less than one hour. Especially if there are more than 1 person in the room or if the panel has been manipulated.

POL