Usually a normal crossover can accept 2 wire input. one +ve input and one -ve input from the amplifier (2-channel)

bi-amp is those components which can take (2 x 2-channel amplifier)
bi-wiring is those components which can take (4-channel amp x 1)
-------------------------------------------------------------------------------
They can accept 4 wire input, which are
two +ve input and two -ve input from amplifier
(4-channel or 2-channel x 2)

This post has been edited by Cola: May 3 2006, 07:34 PM