I'm about to rebuild my HT with a false wall and and a AT screen, and I think the SBA with a absorbing back wall looks like a very good solution for the bass issues that's been troubling me for the last six years. I've used some different sub setup over the years, and spent a lot of time crawling around doing measurement with XTZ RA and omnimic. My current sub setup is 4 Rythmik F12 EQed first with a JBL BassQ and than together with the rest of the speakers with ARC in my processor. The bass is OK in the sweetspot, but it's still room for improvement.
My room is 3.3m x 5.6m x 2.4m and I've one row of 4 seats about 3.7m from the front wall.
The simulations in REW looks very promising, and really like the thought of similar bass response for all the seats and that it doesn't change depending on the height. I guess it's possible to EQ any small peaks or dips between 30 and 60hz for the axial length modes that it's not fully taken care of by the absorbing back wall.
But now for the questions
1. On the front wall I've a box for the ventilation( 20x20cm and stick out about 50cm into the room), will this affect the bass array?
2. The frame for the screen and some of the support for the false wall will be in front of some of the subs. Will this affect the bass array?
3. To be able to support the weight of the subs and get them into the right height, I've been looking into using some adjustable workshop shelf(I've no idea if this is the correct English word)
but only using the needed shelfs. Will this have any impact on the bass array. i.e will it reduce the mirror effect from the ceiling and floor so the axial height modes will still be present?
4. Is it any other advantage of using a denser array than 2x2 than to increase the upper frequency for the array? Or to ask the questions in a slightly different way; Is it better to use more cheaper and smaller drivers than 4 killer woofers? I will go DIY for the subs if I decide to go the SBA with absorbing back wall route.
5. Is there any other benefits than to save space to use low profile cabinets like FoLLgoTT have used?