ESL speakers question.

[Ilianh]

On diy esl designs I've seen the speaker start rolling off at around 15khz.

http://www.quadesl.com/speaker/minimite/measurements/panel_response.gif


What can be done to prevent that?

Thinner spacers? but they limit lower frequency reproduction.
Smaller subdivisions? the Fs goes higher
Or how thin the diaphragm needs to be?
Or how about equalisation?

One part of the esl doing only highs using thinner spacers, and the other one only mids? Would this need another audio transformer?

 

[SY]

Getting it flat to 20K

From what I know, get a better measurement mike.

From what I've read, lower the moving mass.

I haven't had a crack at Sheldon's speakers yet, but I'll guess it's the former.

 

[dhaen]

Wait a few years, and it won't matter...

 

[Ilianh]

Wait a few years, and it won't matter...

hehehe, I dont know for in a few years, but right now I can hear up to 20khz, and it bugs me off when there is a lack in the high end.

 

[planet10]

because of the panel size it is very hard to accuratly measure HF. How does it sound?

dave

 

[Ilianh]

because of the panel size it is very hard to accuratly measure HF. How does it sound?

Hum, I think there was a slight misunderstanding here.

I forgot to specify I was about to start a panel, I did not make one yet..

I'm still searching for the stator grills

The graph I posted was taken from www.quadesl.com simply to demostrate the roll-off at the 15khz+.

Anyway, What I was thinking to do is a 100cm x 30cm panel, to be able to cover from 500hz to 20khz.
And I was not sure of how this kind of relativly small panel would cover down to 500hz (at somehow nice spl's) whitout compromising the response up to 20khz.

 

[dhaen]

In all seriousness this time...

Hi,

I expect Sheldon will post here shortly. What his site doesn't say, he probably knows about ESL's. After all, it's his graph.
Username: stokessd

Cheers,

 

[AndrewJ]

the top end response of electrostatics is dependant upon many factors....hole size and depth in the stators, diaphragm mass, and transformer design to name a few.
An excellent reference book to read up on all of this is the "Loudspeaker and Headphone Handbook" edited by John Borwick. ISBN 0 240 51371 1
It contains a chapter written by Peter Baxandall, a life long friend of Peter Walker and is the most comprehensive treatment of electrostatics published.
It is not however a practical guide to DIY.

Andrew