I've been playing around with placement and calibration of my 2 DIY subs... heh its an ongoing process. I've currently gotten the placement so the majority of the viewing area gets either the output of one of the subs or the combination of the two but one side of the viewing area gets a nasty cancelation of the bass to the point you can barely tell they are on. Very frustrating. I'm too poor to buy a EP500 (or HSU/SVS for that matter) so I continue down the tweaking path.