idea for a planar driver

[m@]

hey everyone. this probably won't work, but I had an idea for a planar driver that is not dipolar.

what if you used a membrane (mylar or alu) mated with an appropriate spacer to an unetched PCB board? it would be like a single-stator esl without air moving through the stator. sound would only come from the membrane side.

you could then charge the membrane with a static charge. or ... possibly charge them with dynamic opposing charges ... if there would be any advantage to that and if it's possible.

anyone have any thoughts?

[Kalimor]

Hi,
I don´t think that would work very well.
If you would use just one stator with a static charged membrane you wuld loose sensitivity, but with the idea of having the membrane loaded dynamicly that could be avoided.
But to do so you would have to have a highliy conductive foil (maybe a metalized one), which in most cases (as far as I read) looses conductivity after some time.

But the bigger problem that I can think of is the pressure building up between the foil an the stator (since it does not have any holes). And since the force on the foil is realy small it would result in a really low sensitivity and maybe bad response time.

A long cabinet behind an ordinary els or a open damped one might be a solution.

Greetings
Christian

[bear]

been done.

It's a single-ended ESL.
Inexpensive ESL tweeters have been made this way.
Works ok for low level signals, but is obviously non-linear as the signal level increases.

There is also the issue of reflections from the rear surface.
Usually the front is the stator, and it is perforated metal, the rear is enclosed behind the diaphragm.

_-_-bear