[sdiy] OT: modeling speaker back-EMF?

[anthony]

Just a second ago I was thinking about that stereo compressor that Peavey 
makes that uses EL84's and I was thinking how cool it would be if you could 
use it for purposes similar to using a small single-ended amp for recording 
in a studio. I was thinking about all of the parameters that one would have 
to take into account to model that situation precisely. One of the trickiest 
I thought of was modeling the behavior of the speaker as it travels. Even 
though AC current is flowing through it making it making it go back and 
forth it seems liek at the point where it changes direction and indeed even 
when it is moving that some back EMF will be generated from the voice-coil 
moving through the magnetic field of the magnet. I imagine the effect would 
be similar to a choke and that simple kind of circuit could be used to model 
it, but my real question is: would someone even WANT to model it? Are there 
any euphonic artifacts here? I think "damping" has to do with this 
phenomenon, but I really don't know a ton about it. I mean I've heard the 
word tossed about.

I do have the super-cheap and awesome Dover edition of Harry F. Olson's book 
_Music_Physics_and_Engineering_ (formerly _Musical_Engineering_). I'll bet 
he covers it in there. This book is old, but nowhere near dated. I'm using 
his charts on Just Intonation note frequencies to make an all analog 
quantizer for Just Intonation.

Are there schematics on the web of compressors using biggish power pentodes 
instead of triodes like12BH7's or something similar?

aa