The Left-Front to sub 200-20Hz AVIA sweep gives me a gap just around 80Hz (with the crossover at 80) setting the crossover to 100 or 120 has no effect on the location of the gap, which leads me to believe that it's not phase related (but I tried flipping the phase switch anyway, and it didn't help) When I ran the LFE 100-20hz sweep again, the subwoofer has a steady -25dB gap until 65dB, after which the response is flat (but +25dB higher) thanks to the BFD. I then set the crossover to 120, so the nearly the full bandwith of the LFE channel should be used by the sub, right? Nope, no change... The mains are not making any sound during the LFE sweep, so no cancellations are possible. I can't be having a room-gap from 120 to 65Hz, can I? If so, how do I go about solving it? Do I have to find another spot for the sub?