fg box, how much polyfill

[zdoc 0]

I finished my fiberglass box yesterday for 1 15" icon yesterday, kinda anyway. Its a little on the small side at 1.8 cubes. I plan on adding some polyfill to bring it up to ssa's specs for 2-2.5 cubes. I just dont know how much to add, I have a 20 oz bag of polyfill at the house. Any advice?

[Acidburn 10]

1 lb per cubic foot

[zdoc 0]

So I should put in almost 2 pounds of polyfill?

[lithium 358]

try half that bag and see how it sounds.