The purpose of biamping is to separately control the speakers highs and lows. This requres an active XO. No biggie. Behringer and DBX make nice analog XOs for less than $200.
You plug your CD or preamp L/R ouputs into the XO. From there, the low/high specific interconnects go from the XO to the amps.
You plug your CD or preamp L/R ouputs into the XO. From there, the low/high specific interconnects go from the XO to the amps.