Bass Traps

GIK Monster Bass Trap with FlexRange Limiter works very well between 75hz and about 300hz, while not absorbing much above that.  Anything below 75hz really needs a tuned membrane or limp mass membrane, like the GIK Scopus.  Don’t get me wrong, the Monster Bass Trap will do some absorption under 75hz, but not as good as tuned/limp.  I have used both.

Thanks! Did you find the limp membrane traps were mostly effective with very low frequencies or were they reasonably broad?

I didn’t really test.  I made limp mass for 63hz, and am in the process of making a set for 50hz.  These are two bass nodes in my room.  Google for “tims limp mass” to see what I did.  One of the mistakes people do on these is to use Owens 703 for the damping.  The 703 is too dense and actually reduces the box area.  I used acoust-a-stuff from parts express.

My understanding is that they are somewhat narrow, but will absorb some surrounding frequencies also.

That's the limp mass plan I've been looking at. Thanks, I'll have to do the math and find my nodes. Room sweep analysis is just showing slow bass decay, not any consistent peaks.