bi-amping a speaker

I recently stumbled upon a NIB pair of array 1400's and have never bi-amped a speaker before.  For now - I'm using a marantz 7011 and plan on simply setting it up in 5.1 with the front pair bi-amped... 

The center is an array 880 and the rear = array 800s

Later on I'll add the necessary high power external amplifiers 

Anyway ..is there a particular crossover range typically used in biamping speakers?