Biamp? How does this work?

Bi-amping works for me also. You can also use solid (1 male to 2 female ) audio adapters (phoenix gold or monster) out of your preamp. But, you need twice the number of interconnects and speaker cables. Depending on the amplifier and speaker, this can make a big difference or you may notice little change. Classe and others make 6 channel amps that may suit your purposes better as far as matching tonal charachteristics of amps. I would get the audio adapters and borrow cables/interconnects to see whether this works in your system. Good luck.

You cannot biamp a biwireable, or tri-amp a triwireable speaker using 2 amplifiers. Your triwire terminals connect in this way:
hi terminals connect to a high pass filter consisting of capacitors and maybe inductors, then on to your tweeter.
Your mid terminals connect to a bandpass filter consisting of capacitors and inductors, then to the midrange.
Your bass or low terminals are connected to capacitor/inductor low pass filter, then on to your woofers.

You cannot tri-amp unless you run your preamp signal out to a 3 way active/electronic filter,(active crossover), which splits the signal into bass/mid/treble outputs. The hi-pass xover output then drives a seperate power amp connected directly to the tweeter. The mid pass xover output drives another seperate power amp connected directly to your midrange. The low-pass xover output drives a 3rd seperate power amp connected directly to your woofers.

You would need to open up your cabinets, remove all the passive xover components,(ie; the inductors and capacitors), and solder the tweeter terminals directly to the set of hi-pass terminals on the cabinet back. Then do the same with your mids and woofers to their respective cabinet terminals. You will then need a 3 way active/electronic xover, and 3 stereo amps.
The xover has level controls for setting frequency, and relative loudness levels between the bass, mid, and tweeter speakers in the cabinet.
Bi-amp assumes a 2 way system. Bass and mid/tweeter. You need the same direct connection of drivers within your cabinet, a 2 way active crossover, and 2 stereo amps.

Excellent response Mg16-- I know I learned something. I've been messing with vertical bi-amping, but horizontal tri-amping, which is really what Nbt is really talking about, is a different and much more difficult breed of cat. Thanks. Craig