Hey all,

I am at the point that I needs to put up the treatments for my screen wall and have a question about the bass traps. My screen wall sits about 16" from the drywall at the front and I am planning on some corner traps there. I can only fit a 12"x12" trap due to my narrow room (10'-6"). This gives me a face width of 17" on the hypotenuse so the traps is full all the way to the walls, similar to what others have done with triangles of material. I know bigger corner traps would be better but will this help at all? I really can't go bigger due to speaker placement behind the screen.

Comments are appreciated.

Yes, I think you'll be fine. It is definitely better than nothing. If you can't fit more, you can't fit more.

That will get you an 8.5" depth from the middle of the front face to the back corner, up to 12" depth to the back corner parallel to the walls. That is enough to do some deeper absorption then any 1" or 2" wall traps will do.

When you say you can't go bigger, what is the issue? Is your screen acoustically transparent? Is the issue you that you can't come further out into the room than 12" (front wall to screen direction), or that you don't want the bass trap to go further than 12" from the side-wall? If it's both, you are doing what you can. If it's only one, consider an asymmetric trap. Go 12" x 16" (all the way out to the screen wall), or 24x12" (the 24" going behind the AT screen if you have one). There is no magic reason to do a symmetric trap (that I'm aware of) other than the fact that it is relatively easy to cut the 2x4' fiberglass boards that way.

Yes, I think you'll be fine. It is definitely better than nothing. If you can't fit more, you can't fit more.

That will get you an 8.5" depth from the middle of the front face to the back corner, up to 12" depth to the back corner parallel to the walls. That is enough to do some deeper absorption then any 1" or 2" wall traps will do.

When you say you can't go bigger, what is the issue? Is your screen acoustically transparent? Is the issue you that you can't come further out into the room than 12" (front wall to screen direction), or that you don't want the bass trap to go further than 12" from the side-wall? If it's both, you are doing what you can. If it's only one, consider an asymmetric trap. Go 12" x 16" (all the way out to the screen wall), or 24x12" (the 24" going behind the AT screen if you have one). There is no magic reason to do a symmetric trap (that I'm aware of) other than the fact that it is relatively easy to cut the 2x4' fiberglass boards that way.

Paul,

The width and depth of my room are pretty much limiting factors. My room is only 10'-6" wide. I will be using an AT screen and want to place my L/R speakers as far to the sides as possible. This limits where I can put traps. And I can not put my screen wall farther out due to seating distances and access to the room from the rear.

I was planning on triangular traps since that seems to be what more people do. I can however make traps that are 16" deep and 8" wide. This would however place my L/R speakers 4'-3" from my center (using Ascend 170s or 340s) and the L/R right against the side of the traps and spaced almost 9' from center to center. I am afraid that this spacing is too close together, but looking at the Dolby site 22-30 degrees off center is optimal and I am at 25 degrees in the front, center seat and 17 degrees in the rear center seat so I may be OK. THX is not loading for some reason so I am not sure what they recommend but it is probably similar.

What do you think of this option?

John

As soon as you get into 'how close can my speaker be to my bass trap', you get past my level of expertise. Personally, I would prioritize correct speaker placement over a few more inches of bass trap. Get it as big as you can.

As to triangular vs. rectangular, it seems to me rectangular would give you more depth, but I'm not sure if there are disadvantages to rectangular...