Originally Posted by sebberry
Bi-wiring on its own does nothing, bi-amping implies bi-wiring.
There is little if any benefit to bi-amping a home theater setup.
Bi-amping would be good in a car for example, where each tweeter has it's own amplifier channel separate from the woofer. This would allow for EQ of each speaker independently as well as time alignment since all the tweeters and woofers are at different distances from your head. This isn't a situation you have to compensate for in a home theater setup.
My A9s and two Adcom GFA-555mkIIs would disagree with you. My A3000 is rated (but likely goes a bit higher than) 140w/ch. I'm only considering the mains in stereo for this argument right now. Each of my Adcom amps powers a single A9 speaker in bi-amp mode. I'm not talking bridged, I'm talking bi-amped. So I've gone from 140w/ch (each speaker in total) to 200w/array for each speaker.
Whereas I could barely get my A9s to preferred movie listening levels before they started sounding like the A3000 was having trouble keeping up, I can push the A3000's volume all the way up to +10.0 with no audible issues. And my center/rear channels have more power to use on top of that. And considering I'm using an A6 for my center, it needs the extra juice.
Yes, I'm losing some power to the speaker's passive crossovers (each array has its own) in the form of heat dissipation, but the power I gained from the bi-amp far, far
exceeds what I lose and I get to go louder without distortion as a bonus.
The real "difference" in sound (levels aside) that the bi-amp made weren't from the power, but the method of bi-amping. Since each amp controls only a single speaker (verticel bi-amping) instead of each one controlling one array for both speakers (horizontal bi-amping), I've eliminated the crosstalk between the two amps. That
is where the improved clarity comes in (which does fit in with your side of the argument that bi-amping alone doesn't improve the audio quality).
Bi-amping will give more power (if you use external amps), but unless you alter the connection method to use a specific setup like I did, the audio won't change, only the levels at which you can produce the audio will change.
Crosstalk elimination was verified using an SNES audio emulator via WinAmp and SNESAmp set to full channel separation (no crosstalk as opposed to what the SNES' real hardware does, which is 20% cross-fade between channels). With the speakers on the A3000 solely, I could hear right channel info on the left channel faintly. With the A9s on the Adcoms, no channel info is mixed.
My speakers are as follows:
Polk RTi-A9 x2 (Front)
Polk RTi-A6 x1 (Center)
Polk TSi-300 x2 (Surround)
Polk DSW MicroPro 4000 (Sub)
The TSi speakers are close enough to the RTis to use virtually seamlessly without the ungodly price of the RTi-A3s.
Oh, and to give you an idea what the power reserves of the two 555s really is: I can have the volume at 0db on the A3000, turn off both Adcoms and the speakers will play at full levels for about 10 seconds. I'd like to see the A3000 do that.