i have down loaded build a better bass trap. great advise. the question that i have is, why did you spec 1" rigid insulation in all of them? was that because you found it to be an easily obtainable material or does 1" have some kind of acoustical value over 1 1/2"? i have access to both.

the second question is, can one substitute the pine frames for MDF? and the 1/4" and 1/8" plywood for masontie hard board? i find them a more stable material to work with and much more dense and rigid.

thanks in advance

Hi George,

Welcome to the forum.

> why did you spec 1" rigid insulation in all of them? <

Because that's the design I was given by the acoustic consultant who showed me how to build them back in the late 1970s. I have built many traps using one inch fiberglass and they always worked very well.

> does 1" have some kind of acoustical value over 1 1/2"? <

I'm sure using 1-1/2 inch thick rigid fiberglass is fine too, but it won't fit inside the high-bass trap.

> can one substitute the pine frames for MDF? and the 1/4" and 1/8" plywood for masontie hard board? <

The problem is I've never tried those materials and measured the results. I have measured traps built as shown in my plans, so I can vouch for them. I'm sure MDF will be fine for the side rails since those rails are just for support. And I'm sure Masonite could work if you figure out what thickness has the same density as the 1/4 inch and 1/8 inch plywood specified. I think someone here once posted the density for Masonite versus plywood, so you could search this forum for "Masonite" and look for that post.

--Ethan