Bi-amping with 2 2ch amps


I have one Pass X-150 and want to bi-amp.What is the best way to go about this staying with 2 X-150's. My pre is a Pass X2.5, speakers are vandy 3a sigs w/2 2Wq's. Thanks for any imput !
samhar
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try horizontal too. The amp might prefer more similar loads in each channel.

ET