I disagree with almost everything Jostler, Stevemj have posted here, and so do the majority of high end speaker manufacturers, but they are entitled to their opinions.
The actual mechanics of bi-wiring, and special design of seperate crossovers that control what signal travels down each cable are covered in detail on many differnt web sites.
The only question to the customer is do the benefits of bi-wiring overcome the additional cost involved with two sets of cable. Or another way of putting it is do two sets of $500 cable sound better than one set of $1000 cable.