More powerful amp for top or bottom?

The usual answer would be to put the more powerful amp on the bottom, since that part of the spectrum is where most music has its greatest energy levels.

However if you are referring to passive bi-amping, meaning that there is no electronic crossover ahead of the amplifiers, and you properly gain-match the amplifiers in some manner, be aware that you will not be able to utilize the majority of the power capability of the 570W amp.

That is because in a passive bi-amp arrangement the outputs of both amps have to swing a voltage range corresponding to the full-range signal. Therefore the maximum output power of the higher powered amp that can be utilized will be determined by the clipping point of the lower powered amp.

Regards,
-- Al

I'd be careful passively bi-amping with that much of a difference in output power. Bi-amping is a fussy business, usually best to stick with matching amps to ensure impedences etc. are closely matched. Presumably the 2 amps are from different manufactures which could cause problems.

You might find one or the other works better alone with good quality jumpers.

Meiwan...Can you please explain the types of problems that could arise from that great a difference of output power. Also the types of problems from using different amp manufacturers. I'll probably end up with a very similar situation so any advise is appreciated.

Bass definitely requires more power. However, it is almost impossible for both of these amps to increase in volume in a neartly exact fashion. Even if you find a good match at 10 watts, was volume increases one amp may increase at a different rate.

Strangely enough, when I was bi-amping Maggie 20.1's, sound was best with more power on treble and mids. Never would have expected that...