how thick are walls supposed to be to be considered a "wall" in bass trapping

[mike c]

how thick/dense are walls supposed to be to be considered a "wall" in bass trapping?

for example ... behind my speakers in the bedroom, is a dry wall with one 1/4" plywood per side (two pcs total + wall studs, no fiberglass) is that considered a wall? meaning do I have to put bass traps behind the speakers?

another example, behind the left speaker of my HT, is a dry wall with ONE 1/4" plywood + wall studs (no plywood at the back) to the left of it is a concrete wall. meaning the the corner is formed by a concrete wall and half a dry wall ... would it be foolish to put a corner trap there considering the bass might not even be 'congregating' in the "false" corner?

[bpape]

All of those are considered walls - though not very good ones in terms of isolation. The double ply uninsulated wall will actually be worse as it's hollow cavity will ring like a bell. Any and all of those areas are definitely candidates for broadband bass absorbtion.

Bryan

[mike c]

thanks bryan!