The Subwoofer DIY Page - Projects
A car subwoofer for my Grand Vitara
 26 October 2018
After fiddling around with a few ideas for awhile (including a modified vented alignment), I decided to opt for a simple sealed alignment for my car subwoofer, as I wanted as small a box as possible (so I'll have some trunk space left in the vehicle). While the output of the sealed alignment may drop at very low frequencies, I could compensate for this with equalization, once the drivers and amplifier were up to the task, of course. I also wanted the box to be as long and wide as possible, again to preserve trunk space.
 

There are some The picture above details the first step of the process - laying out the "base" for the subwoofer. The box will actually be built on top of this base, ensuring a close fit to the car. I cut a panel that fit into the trunk as closely as possible. The carpeting was removed from the rear to accommodate the base panel. Unfortunately the Grand Vitara has this hidden storage compartment that cannot be removed very easily.  No worries - the box will be built around it.  Another option open to me was to use fiberglass to mould an enclosure around the storage compartment, but I opted not to do that.
 

 

The photos above show the box coming together. On completion, each side of the box will offer about 1 cu.ft. net of volume - suitable for most car audio 12" drivers. I've designed it so the top panels can be removable - just in case I want to try out different drivers.
 

The photo above shows the panels, stained and varnished, with cutouts sized for my JBL 1200GTi drivers.
 

The finished box is shown above.

How did sound?  Quite well, considering that the JBL 1200GTi drivers were designed to be used in vented alignments.

Results
I was quite happy with the sound of this subwoofer.  It wasn't as loud and clean as my previous designs, but it was loud and clean enough, and I managed to save a lot of trunk space in the process.