hobby DIY, enhance car subwoofer

I was looking for a decent sized subwoofer for our car, and requirement was it should perform well with reference to bass but size should be optimum. In the car accessories shop could not find a best match. Sony and JVC had some quality bazooka's, but size wise almost consumed whole of our car boot space. SO I decide to get one the optimum box (locally made) from the car accessory shop and enhance it.

And here is the hobby project in video:




There are several websites explain subwoofer DIY. An example: http://diyaudiocorner.tripod.com/faq.htm

Some points:
1. Air vent
As all subwoofers have air vents, I decided to have one and I got one optimum sized in SP road Bangalore. Wanted it bit longer (but same diameter), but had to settle to what I got.

2. Damping
Mostly one does not need damping material for vented enclosure (makes sense for sealed enclosure). But this box was very small compared to the speaker (13 inch) configuration, decided to go for it. Thought might help in increasing the virtual volume ans well phase cancellation. Difficult to find acoustic insulation material (for such a small quantity) and decided to use Yoga mat for this.

3. Protection and floor firing
And as you see the speaker diaphragm was directly exposed and in the boot space the speaker could be easily damaged during shopping material inflow or out flow. So decided to go for a protection and noticed that it could also act as kind of floor fired effect. http://www99.epinions.com/content_2374082692

Some of the above points might add or do bad acoustic wise, but I am happy with what I did!