Sub Box
One of the stereo-oriented reasons I bought this car is the trunk; there's room to sacrifice to the stereo gods
Box building goes twice as fast when you've got a brother to help out. It was raining nice and hard this day, so Dave and I set up shop on the back porch with a sheet of 3/4" MDF and an array of power tools.
After doing a test fit of the pieces, it was time for a little fine tuning of the joints.
For a strong, air tight box, all joints got a bead of Liquid Nails construction adhesive, which Dave applied with gusto. Don't mess with a Hokie who's got a caulking gun...
The completed box, with a double-thickness for mounting the woofer. The additional layer also brings the speaker up to be flush with the surface of the amp rack, which will sit against the face of the sub box.
The front of the box is sloped to match the back seats, and yeilds a volume of approximately 1.25 cubic feet.
In addition to several pounds of drywall screws, the box is internally braced to provide an even more rigid enclosure.
I was out of polyfill to stuff the box with, but I found a ready substitute...
The sub box fills the space against the back seat and ski hatch between the two rear shock towers, which provide anchor points. It only extends to the lip of the spare tire well, which will remain fully funcitonal.
The dimensions of the sub box are the most frequently asked question. The box is a trapezoid from the side. The inside dimensions are 9.5" at the bottom, 5" at the top, 15" tall (straight on the back, sloping in the front), and the whole thing is 30" wide. Those are inside dimensions, add the thickness of the wood (3/4" MDF in this case) for the final dimensions. The volume of the box is about about 1.3 cubic feet or 1.23 with the speaker.