Odd that you would spend all the extra time and money to bi-amp and change the signal when once it arrives at your speakers IT IS GOING TO GET CROSSED OVER ANYWAY! seems like a waste to me. bi-amping just sums the power inputs, you could achieve that with one, more powerful amp (if passive speaker network). i guess if you like it thats cool for you, but there is no way to get around your passive crossover unless you take it out. so regardless of what you do to the signal prior, it is going to end up the same in the end. i used to do some manufacturing analysis (not really audio design, but how to more efficiently make speakers get them to retailers, etc.) for polk audio and while on that project i had the chance to ask them about why would one bi-amp and then said its pointless for passiver crossover speakers. you could instead of buying two lesser amps for price A, instead buy one better one for price A and be better off. obviously i asked them more questions about it than that and they said more than that, but that sums up what they said. YOU ONLY BI-AMP ACTIVE CROSSOVER NETWORKS (NOT PASSIVE SPEAKERS), UNLESS YOU JUST WANT MORE POWER AND WANT TO UTILIZE EXISTING AMPS.