Originally Posted by hippiedave
Thanks, I'll go over there and browse and participate.
I guess if the Denon's do have discrete amps inside for each channel, I'm still confused on how that differs from having discrete amps in different boxes.
Not 100% sure I understand your confusion. I will try to answer what I think you may be asking.
You may be thinking that each amp is fully independent. The amps are dependent on a shared power supply.
Power is likely limited by the power supply being unable to keep up under heavy load. In this case the voltage it normally supplies may sag and clipping will occur. Another possibility is that the receiver's protective circuits may limit voltage in an attempt to protect itself. In either case, having more amplifiers for a speaker seem unlikely to help.
If the biamping was active, that could help limit peak voltage, because the peak signal is lowered for the low/high signal by filtering the total signal into a low and high signal (I mean a signal with the low freqs and another with the high freqs.) It's hard to explain, but with active biamping, by splitting the signal up like that, you reduce the voltage of the two resulting signals you get from filtering and thus reducing the onset of clipping.
So when you passively biamp, you are probably not adding power, because total power is likely limited by other factors. And you are feeding the two amps involved with identical signals...the only difference is that you spread the load to two amps. But one is likely working much harder, because the high frequency side of the biamp almost certainly needs significantly less power. But the total power needed has not changed as far as I can tell.