My box was leaking air on the bass side, some of the foam had dissapeared.

I bought a sheet of foam from the arts & crafts store after failed attempts of finding anything @the the hardware store. I cut a rectangle out of it and put it on & screwed the accordion shut. No more air leaks!

I was skeptical but the sheet was cheap and since its cut into 1 piece there is no place for air to come out.

Plus there are lots of colors to choose from

Dave