Originally Posted by commsysman
As an experienced electrical engineer and circuit designer, I understand the concept of amplifer instabilty completely.
Interesting. I took PhD level classes in automatic control systems, and I don't think that even the guys who taught me would say that. I should note that my spell checker is pointing out that you misspelled both of the words amplifier and instability, which means that strictly speaking, you don't even know how to spell the words! LOL!.
It actually occurs mainly because the power supply becomes overloaded and cannot deliver the peak current that the amplifiers are TRYING to deliver to the speakers on transient peaks.
Reality is that over the audio band a well-designed power amp has 90+ dB of power supply rejection and the power supply itself has these big filter caps that supply most of the current for really large peaks.
Based on watching 100's of power amps clip on my test bench over the last 50+ years with both resistive and loudspeaker-like loads, I don't recall any that became unstable during clipping. This includes some cheap stuff that was pretty marginal. I would call any power amp that became unstable when clipped a POS.
It certainly has EVERYTHING to do with how many speakers are connected, because all of the amplifiers draw current from a common power supply, and each additional speaker requires additional current, which increases the possibility of overload and the resulting instability.
If you had the proper education and experience, you would understand that we are talking about AMPLIFIER DESIGN FUNDAMENTALS; yet you act as if there was something questionable about it. You need to understand your limitations better before you get in over your head on a technical matter like this.
I would say that someone who can't even spell the words right, and makes all sorts of exceptional claims that describe things that are rarely if ever actually seen in real life might be experiencing water
up to his chin or above. ;-)