Soundhound:

Excellent explanation of the crossovers. My experiments with the AR speakers and reading of the User's Manual for my NHT ST-4s agree competely with your post. The ST-4 manual states that bi-amping config provides greater dynamic range and allows the subwoofer section to become a powered subwoofer. The sub statement I can buy, I think the dynamic range thing is debateable.
The user manual simply sez that some people beleve that bi-wiring can bring about soun improvements.