The deployment of the speakers and listening position is constantly varying, so I hope to keep the discussion general and related to the possibility of soaking up low frequency bass backwash. Will that generally work, or is there some flaw in the concept? A few general parameters follow:
The room is 18' deep, 23' wide, and 8' high. Speakers along the long wall, placed out from that wall from 3 feet to about 8 feet.
Listening position varies, naturally, but I try to keep it far enough from the back wall so as to avoid bass enhancement from proximity to the wall.
20" tube traps in corners. Various Realtraps and Echobusters here and there.
For present purposes, let's assume speakers about 4.5 feet from the wall, 10 feet apart, listening position about 5 feet from the back wall. The 1/4 wave cancellation centers at about 63 Hz (86Hz/distance from wall in meters), and corresponding hump is at about 126Hz. If I deploy like this, the measurements with an SPL meter are uncannily precisely just like the calculation. Indeed, no matter what the distance to the wall, the cancellation is as calculated.
I've had very good luck attenuating floor and ceiling reflection cancellations with Realtraps, so I would hope to be able to extend the concept to the front wall reflection, despite the fact that it is a much lower frequency.
Thanks for giving it some thought.