How do I build a sub box?

I'm going to build a sub box= HELP ME?

• Ok, I have all the materials to build my single 12" subwoofer enclosure. I have 3/4 MDF, glue, screws, etc. I have some questions. I don't want to buy a box because I have all the materials. The sub is 1 12" Kicker Comp 150W RMS 4-ohm. Anyway, I'm thinking about building the box at 17-3/4 Width, 14-3/8 Height, 13-5/8 Depth 1, 10-7/16 Depth 2. Will this work. The sub says it needs 1.25 cubic feet volume. A website I looked at said the dimensions for the box was 1.27 cubic feet volume. Will these dimensions work? I plan on building the box Friday. Need an answer tomorrow so I can draw it out. Btw it's going to be a sealed box. And can I use poly fill inside of enclosure also? And where would I get poly fill. This is enclosure is going to be in a ford ranger ext. cab. Will it sound ok if I do it this way? Thanks. 5 for best answer!!

• Answer:

  Everything sounds like you have a good plan. If those are external dimensions, that box is fine. A sealed enclosure allows you ~10% variation in size, so even as large as 1.375 cu/ft and you'd be OK. You don't need poly fill. Poly fill is only need on enclosures that are on the small side, and can sort of "fool" the woofer into thinking it's in a larger enclosure by damping the sound waves inside the box. Since your enclosure is a little on the large side, poly fill wouldn't work well for you.