Gfields,
Ljgi has summed up the situation well. I'd like to clarify one point, though. If you use an active crossover (like the Bryston 10B), you'll only need a single preamp output. You'll connect your preamp to the active crossover and then connect the crossover to your power amps. This is called active bi-amping.
You can also connect your pre to multiple power amps and then connect the amps to the speakers. This is called passive bi-amping. In this case you'll need multiple preamp outputs or Y-cables.
Ljgi has summed up the situation well. I'd like to clarify one point, though. If you use an active crossover (like the Bryston 10B), you'll only need a single preamp output. You'll connect your preamp to the active crossover and then connect the crossover to your power amps. This is called active bi-amping.
You can also connect your pre to multiple power amps and then connect the amps to the speakers. This is called passive bi-amping. In this case you'll need multiple preamp outputs or Y-cables.