# False screen wall or corner trap absorbers?



## patchesj (Jun 17, 2009)

I have 6 2x4 panels of rockboard from ATS. My entire front wall is already covered with the stuff and I'm getting ready to start building panels to surround my screen, a false front wall. The room is roughly 13.5' wide, 7.5' tall and 18.5' deep. The panels on either side of the screen will be 20" wide and floor to ceiling. I was thinking about building the rockboard into the screen wall panels to give two layers of absorption along the front, the screen wall sits about 18" off the "real" front wall. So my question is do I: A) build into the screen wall panels as planned, or B) Make the front corners 3X thick by just stacking the extra panels in in front of the existing wall covering, C) install the extra panels at a 45 degree angle and on the side wall in the corners creating a 24x24x24 "hollow" triangle? Thanks.

I also have 4 - 2x2 panels and 1 - 2x4 panel along the back wall and next to the rear seating position.


----------



## bpape (Sep 14, 2006)

Straddling the corners with at least 4" thickness will give the best performance as long as you already have the wall behind the false one covered. No need or particular benefit to doing a double layer on the entire front wall.


----------



## eugovector (Sep 4, 2006)

Single layer being 2"?


----------



## bpape (Sep 14, 2006)

What I was referring to was having 2 layers of any thickness with one being on the real room boundary and the other in the false wall. The whole point of a false wall is for it to be essentially invisible acoustically and provide hiding of equipment, etc. and a way to get the screen closer to you and/or use an AT screen without having to do in-wall speakers.

Bryan


----------



## eugovector (Sep 4, 2006)

Ah, I misread and thought he'd be doubling the thickness on his "real" wall.


----------



## patchesj (Jun 17, 2009)

bpape said:


> Straddling the corners with at least 4" thickness will give the best performance as long as you already have the wall behind the false one covered. No need or particular benefit to doing a double layer on the entire front wall.


OK, let me see if I have this right.. 
The red is existing 2" rockboard 60 (6lbs/ft), front wall if floor to ceiling, rear/side wall panels are 2x2 or 2x4.
Light green is false wall (to be covered with AT black material).
Dark green is screen (AT material)
Brown was my plan "A" to put the extra rockboard in the panels flanking the screen
Pink was my plan "b" to put double layer on the "real" front wall (actually creating a 6" layer 2' wide, floor to ceiling)
Blue is my understanding of the suggested best approach, double layer stradling the corner with an air gap in the back.


----------



## bpape (Sep 14, 2006)

B will work OK. Straddling as in the blue will work lower. A is not recommended.

Bryan


----------



## patchesj (Jun 17, 2009)

Thanks Bryan. I'm going to build the frames over the weekend. I want to make sure I can pull the corner traps out if I need to, it's a tight squeeze to get back there as it is and I want to be able to get behind the screen.


----------



## hddummy (Mar 9, 2007)

My theater is planned to be very much the same as yours. I am planning my false wall about 24" from the real wall and I am going to use corner traps like you show in blue above. Incidentally, I plan on mounting my screen with a french cleat to the false wall to gain access to the speakers behind.


----------



## patchesj (Jun 17, 2009)

hddummy said:


> My theater is planned to be very much the same as yours. I am planning my false wall about 24" from the real wall and I am going to use corner traps like you show in blue above. Incidentally, I plan on mounting my screen with a french cleat to the false wall to gain access to the speakers behind.


My screen is secured from the back (in the center top and bottom...), but actually slides in from the front if that makes sense. I might contemplate a french cleat or other arrangement. I went with the slide in approach so the weight of the screen is distributed across the entire bottom and the frame is held square, no worries of sagging or warping. I might try to move the screws that secure it in place over to the sides of the screen, should make it easier to get it in and out.


----------



## patchesj (Jun 17, 2009)

bpape said:


> B will work OK. Straddling as in the blue will work lower. A is not recommended.
> 
> Bryan


Going to build them as drawn with the "blue" plan. How critical is it to achieve a seal between the sides of the traps and the walls? I could cut the base and tops at 45s so the trap tucks nicely into the corner, but then it would also make sense to trim the rockboard to fit against the sides, probably taking 2 inches of the rear piece. Or I can build the traps square, and keep the rockboard intact, but then the trap is only in contact with the walls at the very back edge of the sides.

Thanks!


----------

