planning a glass box.... advice please!

[Rogers]

ok so im going to be starting a fiberglass enclosure for my reg cab truck tomorrow.... anyways its going to be an odd shape... so im wondering how im supposed to determine how big to make it... im doing 4 rex8's and i need .35 cubes for each woofer so i need a total internal volume of 1.4 cubes... anyways im going to be making the enclosure an exact mold of the floor.... there are humps in the floor for the transfercase and tranny... so my question is... how do i determine how large to make it.... i mean its not as simple as going to a box calculator and entering in numbers... so is it just a guessing game or what?

[raytard]

make it as big as you can reasonably do so, and install the subs and test it, some guys will tell you stuff about filling it with sand or fluff or peanuts or whatever, but thats a whole new kind of hassel and inaccurate to boot

play them, if they sound like they cant drop low, or are overly punchy, pack it with some polyfill. if they sound loose or lost their punch, pack some modeling clay into the box as a ghetto 45 just to take up some airspace. if it sounds right then congrats, you got lucky

this is an imperfect science, and that .35 is a suggestion, not a requirement, so get building