Chris, welcome. If the "bi-amping" that you mention is simply hooking up the back surround channels to the mains, forget it. This isn't biamping and is still limited by the available power from the one power supply section in the receiver. Available maximum power isn't doubled, as some imagine, or increased in any amount.
As to whether this available power would be enough for your use with M80s, this would depend on how hard and for how long you work it. In most cases it should be sufficient for the M80s, which are slightly more sensitive than average and require less power than many other speakers, whether rated at 8 ohms or 4 ohms. Factors such as your listening distance, sound level you use and dynamic range of the material you play are key factors.
I've come to realize the bi-amping thing via the receiver isn't worth while. Thanks for the explanation as to why.
Dewd mentioned that Onkyo receivers don't work well with 4 ohm speakers. Are there any Onkyo/M80 owners out there that managed to get them to play nicely together? I've heard that the M60s have slightly subdued mids and highs compared to the M80s which have a more balanced overall sound. I don't want to look back with any regrets so I'm open to suggestions to all you knowledgeable forum folk out there in Axiomville...
My room is approximately 25 ft across by 15 ft deep but the entertainment centre is offset to the left side of the room. I can re-arrange things once I get a game plan going. I won't be "rocking out" very often so music levels will be kept to nominal levels...
Cheers,
Chris.
