Ran out of PE sonic barrier, need alternative

[silvercans]

So it looks like I miscalculated on the PE sonic barrier (1/2") and because shipping is probably more then the product, I need to know what you recommend that I can pick up locally?

[BobEllis]

How about chopped foam carpet pad? I've used it with satisfactory results, sometimes doubled up. Quite cheap, and you'll have something to use until you can tack some sonic barrier onto your next PE order.

[EdL]

And consider adding peel & stick vinyl tiles ( $0.99 ea. @ your home supply store ) between the case and foam for "mass" damping.

[BretH]

I take it that this sort of stuff doesn't reduce the inside dimensions of the enclosure by the thickness of the material? Because the low frequency waves more-or-less go right through the foam?

[silvercans]

I was at Walmart today and noticed they had polyester batting that was ~1" thick, and 24"x24". It looked just like fiberglass batting in terms of stifness and density. What do you guys think? (fyi I can't use the fiberglass stuff because my speakers are ported).

[BobEllis]

give it a shot. I liked the results with carpet pad better, though.

[eperson]

I went to one of those Jo-Ann craft stores, and they have sheets of open cell foam from 1/2" thick to 5" thick that are really cheap. I think I got a 2'x6' sheet of 1/2" for 10 bucks or so.

[peterS]

I take it that this sort of stuff doesn't reduce the inside dimensions of the enclosure by the thickness of the material? Because the low frequency waves more-or-less go right through the foam?

they simulate a larger enclosure actualy by having more give

[ThomasW]

Thin material of any kind has little to no impact on the bass or the size of the box. It does absorb any higher freqencies that aren't filtered out by the crossover. With the expanded foams it takes a couple of inches before there's much benefit.

The carpet foam Bob's talking about is much denser than mattress or acoustic foam. With carpet foam one has to be sure that the bonded side is glued against the enclosure walls so the open cell side faces the driver.