Custom trunk and subwoofer enclosure
I built a custom "instatrunk" that also houses my subwoofer and amplifier. I had one of these in my old YJ in college, and actually still had the old sub and amp, so I made another to fit my TJ. It's basically 3/4" MDF with 2.25" drywall screws holding it together. I used silicone to seal the joints both for acoustics and to keep the rain out (that we get about 2 x a year). The internal volume for the sub is 0.60 cubic feet, unusually small for a 10" sub, which is why I chose the Kicker Solobaric way back when. The paint is Krylon flat black I had laying around, over some Krylon gray primer I also had laying around. I plan to cover the top with carpet or something, but I'll get to that eventually.
The back seat still folds and tumbles due to the relief cut in the front driver's side corner. However, I have to release and swing the whole seat up on the front hinge first, then when it's up in the air 45 degrees I can fold the upright portion down and complete the process.
I intended on bolting it to the floor initially, but laziness took over. Turns out it fits SO tight side to side that it's tough to move to begin with. Also, with the back seat down and locked and the tailgate locked, it is even harder to pull straight up simply because the seat prevents the larger bottom from coming up. I may still anchor it, but for now it's hopefully not going anywhere.
As far as sound quality, it made a 200% difference! I have a Kenwood HU and aftermarket speakers in all four corners, but it still made a drastic improvement. Especially on the highway, you can still hear all the music. It would be even mo better if my HU had a crossover that could do the hi-pass/lo-pass thing as right now the sub and the four speakers all receive the full spectrum. But it's good enough for now.
I can give any specific measurements or more photos to anyone interested, but the pics here about sum it up.
Shots of all the pieces put together, with the sub's enclosure still not attached to the inside.
Shots of the whole shebang from the front, on the floor and in the Jeep
Out of the Jeep but painted
Installed from the top
Installed from the back