What are some of the things to know about biamping? I am considering this but do not know very much about it.
I need info on the active xover and what not.
MikeL makes some great points. I use two EVC ultimate attenuators in my biamp setup.

But I think in this case it really makes sense to go for the active x-over since you really do want to filter out the bass freqs going to the 300b SET amp for the tweets since your available power is fairly limited.

That should increase your dynamic range allowing for higher max SPL.
If going for the active bi-amping the thing you need to keep in mind is the woofer x-over freq and the slopes of the high/low pass filters of the speaker's built-in x-over. What type of speakers are you planning to biamp?
I am sorry guys that it took me so long to get back to ya.
I have klipsch khorns for speakers, so power is not really
an issue. It's more about what I need and the options I may have. Thanks for all your help. BTW my room is small.
K-horns are so efficient there is really no advantage to bi-amping them. The woofer only goes down to 32 hz in the right room.
Jsman, in specific those speakers will probably have little to any positive reaction to bi-amping,, definatley save the money on buying a processor and additional amps and put it all into a better standalone 2 channel killer amp. You want more power or bass, go with a newer mcintosh solid state and it will nearly sound like tubes, but with rediculous power for the bottom end on that 15" woofer.. I use to own these combinations ...