"...The side wall reflection panels appear to be too high though that likely has nothing to do with the 40Hz problem..."
hi steve,
i followed your room build in another forum -
wery impressive!
but, i also wondered about the location of the side-wall panels, that bryan mentioned; i never posted because i was not a member of that other forum. it would seem to me, that for the side panels to be effective, the listening position (~8" below the top of your chair?) should be centered on those panels, and as it is now, the bottoms of the panels barely reach the top of the chair...
also, if that were my room, i would move the two equipment racks off the side wall, and put them up against the rear wall between the speakers. it seems they are in the way of the main wave-front of the speakers...
from your room-building thread, i know how much time/effort/money went into that room build, but i can't help but wonder why you didn't increase the room's width and depth by another meter or so...
doug s.