bass trap question

[jayjames]

Greetings,
I'm ready to make some bass traps for my live room with some 4" mineral wool boards, and I'd like some advice on which way is more efficient. Should I straddle the corners with the 4" boards, keeping an air gap in the rest of the corner, or should I fill in the corner by stacking triangles of mineral wool to make a corner wedge? I've been told that filling in the entire corner is more efficient but would cost more due to the extra material needed. However, I've read that when hanging wall absorbers, it's best to have an air gap equal to the thickness of material between the trap and the wall. So which method is best for corner traps?
Thanks for reading.
Jay

[knightfly]

A complete fill is better, but may not be ENOUGH better to justify the cost. AT least 4" is a good start, and a second layer behind that would be your next step if you don't want to fill the entire corner. The closer you get to the wall, the less effect.

Reason for air gaps on flat panels is to save money and still get lower frequency absorption; if you had the money, a solid 8" absorber would work a bit better than 4" with a 4" air gap behind... Steve