Active EQ for Sanders' Compact Hybrid ESL

[CharlieM]

If anyone here has built Roger Sanders' compact hybrid ESL? I'm inerested in building the EQ shown on page 176 of Sanders' cookbook but I'm new at this. Any advice, like where's the best place to buy the components, would be helpful.
thanks!
Charlie

[stokessd]

I haven't built it, but I built one of my own in a similar vein:

http://quadesl.com/speaker/diyesl/esl_xo_manual.pdf


Sheldon

[CharlieM]

Sheldon,

Let me guess.... you've done this before.
It looks pretty daunting for a newbie who's never built a IC but I guess it's like eating an elephant 1 bite at a time.
Seriously though... you're a heck of a resource.
My panels (already cut) are 12"x48" so the rolloff wouldn't be the same... still, I'm thinking I could extend the edge baffles in a "U" config to get the equivalent of 20" panels; which would then correctly marry up to your X-over/EQ?

thanks!
Charlie

[stokessd]

Yes, I've done a few circuits before. But I'm not expert by any means (I'm a mechanical engineer).

Take the circuit in pieces, I can walk you (or anybody else) though each step. There's a 4th order low pass for the woofer, and an all pass network to align the woofer phase with the panel. I'm currently not using the all pass though. The panel side has a 4th order high pass and a shelving EQ that raises the gain as frequency falls below a certain point until it hits the 4th order XO.

I wouldn't make the panels wider with wings. If you want to make the active area wider, then that's a good thing (bigger is better with a panel). But to make them wider jsut to use my circuit values is a mistake. Stay with your 13" or so width (with frame), and change the shelving EQ point. The shelving EQ is the top of U4 and U7. You adjust C7 and C24 to change the corner frequency.

The corner frequency (3dB down) is:

Fc = 1/ (2 * pi * R9 * C7)


Sheldon