I want to build a custom box

I was thinking about building a custom box. One that is similar to one of those pre fab truck sub box. The ones that are wide about 28" and depth maybe 10" something along those lines. Does the shape of the box matter that much? I want to build a sealed box with about 1 cubic ft of volume and was curous if the shape matters or not as long as its volume still comes out to be 1 cubic ft.

depends on the sub man. shape doesnt matter i dont think just make sure u got enough volume

The shape dosen't matter as long as the internal volume is good to go. Remember that the external volume of the box and the internal volume are not the same, you must account for the thickness of MDF used. I'd recommend at least 1/2" thick MDF for most high-power (assuming this is high-power) sealed applications. Also, buliding some baffles inside of the box is never a bad idea for support. The box will want to flex when the sub hits, and baffles keep the structure stable. Also, it sounds like you're going to make a pretty large sealed box. Be sure that the volume agrees with the recommended volume for your particular subwoofer(s).

For a good SQ sealed box, the shape DOES matter.

When you build your box, make sure the front and the back panels aren't parallel to each other. This will reduce standing waves inside your box and prevent unwanted frequency resonances. If you do use baffles, remember to account for them in the volume of your box.

Also, make sure to use at least a pound of polyfill to stuff your box and make sure to seal all the internal seems with silicone sealant to make it airtight.

I recommend going with 3/4" MDF too.

For my box, I used 3/4 inch MDF (5/8 is to thin for these subs). The box is sealed and has a calculated cubic feet of 1.3. The demensions are 24" wide, 16.25" tall, 11" deep on the bottom, and 4.25" deep on the top. After the hole for sub is cut, you need to use some left over MDF wood and make at least four 2-inch wide braces and wedge them inside the box between the box face and the rear walls using some type of adhesive. This will provide added support for the box to help prevent flexing when the sub is pounding. It will also be needed if you are going to mount your amp to the back of the box to minimize vibrations to the amp.

You should also use some "L-brackets" and screws to secure the box to the trunk floor. Don't forget about using "t-nuts" or something similar for the sub mounting screws. You don't want to screw directly into the MDF wood (they will strip the wood eventually). Thats how I did it. Here is a link where you can see a couple of pictures of the trunk and box.
http://forum.E46Fanatics.com/showthr...0&pagenumber=3 Just scroll down a little.