Hushbox insulation

[mtcross]

I have a hushbox I made out of a cabinet, and I was wondering what the best way to sound insulate it is. I have read quite a few posts here, but I could not find one that ultimately recommends a type of insulation. Is any egg-crate foam acceptable? I have read that 1" foam is a minimum. Agree? Would acoustic tiles work?

If anyone has any ideas, please let me know. I only have an inch or so in the "tight" spots in the box . I have more room in other places and could even go up to 4" at the bottom for example.

Thanks.

[Tweak]

I would opt to line it with Dynamat or similar stuff, which takes up little space, and then fill the remaining space with moderately compressed fiberglass insulation, assuming you can find a way to seal the fibers in. If you're averse to working with fiberglass or can't seal the fibers in, polyester batting is the next best alternative, but you'll need to use more of it to get the same attenuation as fiberglass.

I'm not a projector guy, but I assume you won't have any low frequencies to deal with. If that's the case, you can skip the Dynamat and just do the insulation/batting.

I'm sure there are plenty of other solutions that will work well.

-Tweak