[rlw3]

which results in tighter and lower bass a 45 degree trap in a corner with air in the "cavity" behind the trap or filling that area with material? what material would be best? would old cloth work well??

[DTB300]

I have 4" traps across the corners (45 degree) from floor to ceiling.  When I added some Bulk Acoustical Cotton behind them, the bass response/sound improved in my room.

[bpape]

Adding more behind will help some certainly.  Cloth will do something but hard to say what exactly.  Something like insulation will work better.

Bryan

[firedog]

So isn't that part of what Tri-Traps do?

[rw@cn]

So isn't that part of what Tri-Traps do?

As some one who is interested in Tri Traps, I would like to second the question?

[bpape]

Yes.  The Tri Traps are a solid chunk style absorber rather than a 4" panel straddling.  They fill the entire corner at 17x17x24".

Bryan