Originally Posted by beaveav
Originally Posted by DonH50
If the bass amp is distorting due to exceeding supply rails, in a passive bi-amp system the tweeter amp is clipping at the same time due to the large bass signal even though it is not putting out significant power at the lower frequency.
Depends on whether we're talking about bi-amping in, say, an AVR, versus bi-amping with something like two completely separate amps, no?
If you have two independent but identical amplifiers driven by the same input signal they will clip the same essentially independent of the load. The situation is the same for two amplifiers in separate boxes or two channels in an AVR. Yes, the independent amps do not share a power supply so may deliver a little more power (see below), but i would expect that difference to be slight (maybe 1 dB or so) at max rated power. IME experience load dependence on the performance of SS amps is minimal unless you go to extremes, and by that I do not mean the speakers 99.999% or whatever of us are using.
The big caveat is AVRs that have weak enough power supplies so that multichannel operation degrades power significantly. Of the 5 or 6 AVRs of different brands that I have in the house, acquired over maybe 20+ years, that is only true of one of them. Even then the only time you might notice is at max volume, louder than I can stand anyway.
If you use an external line-level crossover before the two separate amps to create an active bi-amp system the situation is entirely different, of course.
The general way these arguments go is that, even though the vast majority will see (hear) none of the theoretical benefits of passive bi-amping, everybody is convinced they are The One. I was the same back when I got into this business (late 60's/early 70's), working for a high end store and fully convinced I could hear every nuance in swapping amps, cables, adding rubber feet, etc., but a lot of engineering and numerous tests (blind, double-blind, ABX, etc. in addition to gobs of measuring components) slapped some sense in me despite my beliefs. That said, there was truth in some of the claims, but compared to the wealth of disinformation and hyperbole it was slight. I was shocked and annoyed but have survived despite all that.
FWIWFM - Don
Edit: I do not know if I am the guilty party Arny mentioned that wsa comparing active and passive bi-amping, My apologies if so. I had not heard of passive bi-amping as implemented by AVRs until just a few years ago. Bi-amping to me always implied a crossover before the power amps, either an active crossover using transistors or tubes, or a passive RLC box, but either one operated at line level. I simply never thought of driving both amps with the same signal, seems like such a waste.