I wanted to find a solution for getting a sub woofer into my Xterra with out sacrificing cargo space. I found some plans for an under seat sub on a Frontier forum. I converted his drawing into a simple Google Sketch Up file, and built it. The under seat area seems to be the same between the Frontier and Xterra.
Here are the drawings I came up with based on the above URL:
I used 7/16" birch ply and carefully cut out the pieces on the table saw. It was rather tricky coming up with a cut list. The overall height of the box cannot be any bigger than the above listed height (even a 1/4" would make it too big!)
Once all of the pieces were cut out, I used wood glue and brad nails to hold it together. Once the wood glue dried I sealed the box up with silicone.
Here is a picture of the finished box:
A picture of it installed (excuse the install mess):
It sounded great for what it was. I felt that it lacked low end bass. Before bolting the seat down make sure you do something to sound deaden the underside. I didn't and the seat rattled on certain notes.
