Stick to a 10" sub in that box. I went with this
Polk Audio MM1040D.
It adds just the right amount of bass for what I was looking for. This box certainly does not have enough space to push competition level bass, but that is NOT what I was looking for. I wanted tight, quick, full bass, and this setup gave me just this. I can also turn up the bass on the nav screen, and in the rare event that I am listening to rap (for some reason, girls seem to love that shit when cruising between bars at night...and I dont drink, so please no DD lessons for me!), you get that much stronger bass, without rattling the car, but to the point that it would be uncomfortable to leave the volume as loud as it was before turning the bass up...
Besides that, I love this box, it works out just perfect for the captains chairs... I am in my truck a lot for work, and this has doubled very well as a laptop stand / filing cabinet because of its position in the truck! Plus, the guy who sells them on ebay there is a great seller, and will really help you out if you email him the sub you plan to use and all that. He can make some good suggestions on size, power, and also get you a good deal on the sub if you want to go that route with him!
