Avia phase sweep. SPL meter. Crossover toggled "disabled" on sub. "Large" mains. Bass out to Mains and sub. Main listening position. 10+ dB drop out once or twice in the sweep. Can't recall specific tonal ranges at the moment, but I thik middle of the sub range 70-80Hz is the weak spot. Speaker size settings pretty insignificant. Crossover point changes pretty insignificant. Lows are great - they actually grow into the next higher dB range near the end of the sweep. High sub tones are great. I take it this is the main result of positioning of the sub in the room, and/or the room style/size itself (acoustic cancellation)? It's in a small space for now, until I move. What is a common acceptable peak and valley range? The theoretical ideal I'd imagine to be within +/-2/3dB the whole way through the sweep. More experimenting to do, but thought I'd look for a second.