...Biwiring and bi-amping my BP7001SC...
When you hook up ONE speaker cable (one amp) to EACH BP7001SC, you are IN FACT BI-AMPING it! Your External amp is driving the High & Midrange/Upper Bass Frequencies, and your BP7001SC's internal 1,500 watts amp is driving the Subwoofer Frequency.
If you hook up TWO speaker cables (2 amps) to each BP7001SC, your external amp is still just driving the High & Midrange/Upper Bass Frequencies, and your BP7001SC's internal 1,500 watts amp is still driving the Subwoofer Frequency. Thus, you would be wasting one external amp!!
So, the take home message is, when you use just one amp to drive any Powered Def Techs, you are in fact bi-amping.