Hi, I have 3 x 4 ft window that I want to soundproof against road noise etc. I've cut a 3 x 4' 1/2 inch particle board insert as step 1, and I'm need to determine the best soundproofing material to tack to one side of it.
I'm only looking for standard stuff I can get at Lowes or HD, and it can be up to several inches thick.
Any suggestions?
Thanks