Some people can sit on a small rise above a serene valley on a beautiful spring day and just marvel at the wondrous view. Others never get to really enjoy the view because they get too wrapped up in trying to figure out why it's so wondrous. As Bonnie Raitt sang, "Life gets mighty precious when there's less of it to waste." In my golden years, I much prefer to sit back and enjoy the view, or in this case, the sound of my system, for what it is. I'm happy to let all the young inquisitive minds take my place wondering why it is.
Microphonics, Feedback and Bob Carver
First, I’m going to present a theory I don’t have a lot of investment in, I’m just curious about.
Bob Carver and I, at different times, have wondered about the ability of an amplifier’s feedback circuit to be impacted by a speaker’s natural microphonic attributes. That is, in a room and unplugged to an amp a speaker and microphone are broadly similar. A diaphragm is exposed to sound which moves a voice coil which generates an AC signal in proportion to the acoustic event. Of course, a speaker is a terrible microphone, but it can be one.
The question I’ve had, and then read Bob Carver also asked (but he’s not known for always being right, nor am I 😁) is whether part of the problem with negative feedback in an amplifier is that it can pick up in room sounds (such as from the other speaker) and react to it in a negative fashion.
While this is testable via equipment I don’t have, not to mention time/energy to do it right, I’m wondering if anyone has ever read any more on this subject they’d care to share?