how to apply the 38% rule?

[arjan]

hi folks,

as you can see in the pic, my controlroom has a pentagon shape.
the corner facing the window will be a bass trap. do i apply the 38% rule to the distance from the window to the corner or from the window to the beginning of the bass trap? confused...

thanks,

arjan

[bpape]

You always apply it to hard boundaries, not treatments. In this case, it's not as critical as you don't have 2 parallel surfaces front and back. The bass absorber behind you will do a nice job of minimizing length related issues.

Bryan

[Ethan Winer]

Originally Posted by arjan

do i apply the 38% rule to the distance from the window to the corner or from the window to the beginning of the bass trap?

As Bryan said, modal boundaries are the rigid surfaces. But in a room with that shape there's no flat rear wall. So the only way to know where the LF response is best is to measure as you try different placements.

--Ethan