So the above is my L shaped room with two Mirage BPS-400’s dual sealed 12” subs with two SVS SB1000 Pro sealed 12’s ran off a MiniDSP 2x4HD. This is without smoothing, PEQ or Audyssey applied. For a while I was struggling to get decent response in my room, the 400’s weigh over 100lbs each so I took Gene and Anthony’s advice and put them on dolly's with my UMIK-2 at ear level at the MLP and took a ton of measurements marking where the locations where there was improvements and where there wasn’t. Than used super position with the 3rd and 4th subs as my only equal length corner distances are the front left and right subs. All in all I’m looking forward to seeing if PEQ makes a difference and continued and I want to ensure they’re time/phase aligned. Prior to this I had a guy from one of our very few A/V installer/calibrator shops come by and see if he had any thoughts or input. He appears to have stopped learning about acoustics when absorbing the first reflection point was widely recommended and bass traps will fix everything. When I asked him what about multisub and how effective it is when placed in a null and properly calibrated he told me and I quote “Any properly calibrated home theater shouldn’t require more than a single subwoofer if you treat the room to my specs” needless to say I took the multisub route.