Detailed operation of the QUAD ESL63

[wout31]

Just make things more clear on bass segments and panels.

Green are the delay rings only above 1 kHz.
White is mid-bass.
All the rest is bass.

This is a 4 panel model, for 6 panel models add an extra bass panel on the top and the bottom.

 

[esl 63]

Just make things more clear on bass segments and panels.

Green are the delay rings only above 1 kHz.
White is mid-bass.
All the rest is bass.

This is a 4 panel model, for 6 panel models add an extra bass panel on the top and the bottom.

Wrong. Green area is FULL RANGE, White is FULL RANGE with some low pass, All the rest is BASS/MIDRANGE with more low pass.

 

[wout31]

Small capacitances of the ring areas don't count.

 

[jan.didden]

Green area is FULL RANGE, White is FULL RANGE with some low pass, All the rest is BASS/MIDRANGE with more low pass.

Never looked at it this way, but I think you got a point. The very center of the mid/high area is directly on the xformer outputs, so full range.
Hmm.
The only 'real' lowpass I see is at the end of the transmission line; still not much of a low pass with those 300k resistors.
The transmission line delays the wave but doesn't low-pass it, does it?
Or maybe the panel segment capacitances act as progressive low passes along the transmission lines.

Jan

 

[jan.didden]

Never looked at it this way, but I think you got a point. The very center of the mid/high area is directly on the xformer outputs, so full range.
Hmm.
The only 'real' lowpass I see is at the end of the transmission line; still not much of a low pass with those 300k resistors.
The transmission line delays the wave but doesn't low-pass it, does it?
Or maybe the panel segment capacitances act as progressive low passes along the transmission lines.

I did a quick sim on Hans Polak's model for the '63, measuring the frequency response at several places along the transmission line, so at several sections of the panel. That appears to confirm the fact that most of the panel works full range, with a drop of some 5dB at higher frequencies. The black, lower curve, is at the final bass panel drive and indeed that is low passed. Enlightening (for me at anyway).

Edit: x-axis is 20Hz to 20kHz.

Jan

 

[jan.didden]

Outer ring (6), bass area mid/high panels (7), bass panels (8).
Now with x-axis 😀

Jan

 

[AllenB]

Thread split from here - https://www.diyaudio.com/community/threads/quad-esl63-dust-protection-comparative-testing.427931

Side conversations can be a welcome part of a thread, sometimes a new thread can be even better.