[Rob Babcock]

I've been contemplating a variation on your diaphram bass absborber.  How would it work to add a "spacer" an inch think around the frame of the unit and affix an outside/top sheet of pegboard covered in 2" foam?  It's hard to describe, but it wouldn't touch the diaphram in any way or prevent it from moving.

My thinking is that the bass freqs would pass right thru the foam & perforated pegboard and be dampened by the diaphram.  This should create some real broadband absorption and work well to create an LEDE system that would be effective into the bass region.  Or would it?

[Ethan Winer]

Rob,

Yes, you can space porous absorbing in front of a panel trap so it absorbs mids and highs too. I did exactly that with four of the panel traps in my home recording studio to create Reflection Free Zone. But your proposal is less than ideal for several reasons.

First, foam is not as good as rigid fiberglass. It's easier to deal with, though, so as long as it's at least two inches thick it will help. Much better is one-inch thick 703 or 705 wrapped in fabric.

Second, you really can't use pegboard or any other such material as that will reflect high bass and low mid frequencies. This is another reason to use rigid fiberglass - it's actually rigid enough to support itself.

--Ethan