Sorry it took me so long to write--I had an emergency out of town.Anyway, Since I had extra speakers, I decided to put two extra ones on the bottom in an isobaric configuration and run it from my subwoofer amp (which has a variable crossover). Well, it sounds incredible!! There's just one problem, it hums like crazy!! If you play it loud enough for the neighbors to call the cops, you don't notice it (Damn noise ordinance!). Is there something I can do to kill the hum? I have the sub amp running off of the pre-amp output on the receiver, then looping that from the sub amp back into the receivers "amp in." The receiver only has a 2 prong plug which might be part of the problem, I don't know. Thanks in advace for any suggestions.