I’ve got a 20’x16’ room also, not fully sealed, opens to a stair case at the back, but the room modes that come with this dimension are anything but ideal. Appreciate the tips Haywood and believe you are on the right path.
@audiorusty
That sounds like a good technique for pairing smooth bass with your bookshelfs. I might try that! My Tekton DIs reach down to 30 HZ on REW, and have a flat response down to 20 Hz after Dirac Live calibration. Bass is authoritative down to ~ 40 or 50 Hz using a 48W SET LM508IA integrated. Just because Dirac says I’m getting it, doesn’t mean it’s punchy and as tight as I’d like.
@audiokinesis
That 90 deg. phase idea is interesting. Assuming the use of rule of thirds for speaker and LP placement which I found to be not far from ideal, optimization of placement for a pair of subs on the left side wall, and a pair on the right might work (only 4 variables). Multiple optimization sub placement solutions for different crossover frequencies might further results.
Sub crossover frequency suggestions always seem to be around 40-50 Hz for best integration results with mains that dig deep (no bass management). I’m thinking at those frequencies there are few room modes you are trying to smooth out with subplacement. Do 4+ instead of dual subs shine best in monitor/stat/maggie systems with subs crossed at ~80 HZ?
Decoupling bass frequency from mains allows for smoother room response using multiple subs, but I wonder how anchored in the soundstage 40-80Hz notes from stand up bass would sound.