ESL tweeter efficiency

[blu_line]

I am considering ESL tweeters for my dipole speakers instead of conventional ones.

Is it possible to achieve approx. 90dB with diy esl tweeters ?

grtz

Simon

[Few]

Simon:
The efficiency (or the sensitivity---not the same thing) can be made quite high, but there are other parameters that may have to be traded off. Directivity, capacitance (how hard it is to drive), maximum SPL, bandwidth, etc. will be affected by changes you make to maximize the efficiency. You'll have to think about those other constraints as well in order to decide if an ESL tweeter will work in your application.

[blu_line]

Thanks Few,

I'd like to build a tweeter with around 90dB SPL and directivity as wide as possible.
Operating frequency is from 2KHz (-3dB) uptill ........
The step-up transformer i have is 1:130.

As fas as i understood i can do with 0.04 m2 area and stator-diaphragm distance of about 0.8 mm.

It is very hard to get perforated plates with the correct openess so i think i stick with
enameled wire.


grtz

Simon

[bigwill]

perforated plates are not fun

[blu_line]

perforated plates are not fun

Please elaborate ?
You've got experience with it ?

grtz

Simon

[bigwill]

Originally posted by blu_line


Please elaborate ?
You've got experience with it ?

grtz

Simon

I attempted to build an ESL with uncoated perforated sheets and it went horribly

[blu_line]

Question remains:
How to build a good electrostatic tweeter ?

grtz

Simon

[bear]

There are many sucessful published products both in mags and online. You might want to start with one of them. Modify slightly to suit.

Getting "90db" should not be much of a problem.

But, I'd advise determining what your line source actually produces! Beyond that, I'd consider a bi-amp set up - obviates the matching issues. And you can use a tube amp special made to drive the ESL tweeter section if you wish.

The trade off is between spacing/bias voltage/excursion and maximum input signal which = output.

Then there is the matching... that will change the sensitivity & bandwidth relationship. Lower sensitivity = wider bandwidth in general.

Dispersion depends entirely on the width vs. frequency relationship of the cells you build. Unless you use an external dispersion method.

The "openness" of perf metal is likely not as important as you might expect. 50% or better is ok, fine. It's pretty easy to buy any style of perf metal you want, just look online or find a local wholesale industrial sheet metal shop or better a supplier.

Beyond that, there are many many threads to search here on this topic.

_-_-bear

[blu_line]

Thanks bear,bigwill and few.
I found 2 nice books on the subject (sanders and wagner) and lots of links left by james moray.

grtz

Simon

[bear]

I have "more confidence" in Sanders.

_-_-bear