I've been lurking on slim subwoofers for a long time and then decided to go with the kenwood SW10. I was sold the moment I heard one installed on a small truck and was blown away by the bass it was delivering for it's diminutive size.
Got it installed behind the passenger seat, it only takes about 3 inches of space.
The bass you should expect from this unit is not SPL, windshield shaking type. It's more like an bookshelf speaker type, it's acoustic, it packs a punch, it gets loud but never noisy and you hear it instead of feel it. I used to run a dual 15" Alpine type R 2000 Watt rms in full size enclosure in my old car, I must say this setup is the complete opposite.
It is powered by a 150w amp running a small 5x7 square driver, and a passive driver of the same size in a sealed box. The advantage of having a passive driver is that it extends and "warms" the bass, instead of the cold punch in typical sealed setup.
I've got it paired with a pioneer DVD HU, a rockford T2 component system and the sound is very good, it really had that balance I was looking for. The installers were very pleased by the result, they said the sound quality was quite good for such a simple setup.
At $160 it is costing only a fraction of what a full system would have. Installation is so easy, It took less than 1 hour and basic knowledge in car audio. There is no messing around with amps, wiring, ohms matching.
It's plug and play and you can remove it anytime you want with only 2 connection plugs.
For the tiny size and super light weight (mere 4 pounds) it is the ultimate bass solution for those who want to keep a stock look in their car. Of course it is not everyone's taste, some people might want a bit louder system, but this setup I have is a driver's sound system.
If you have any question feel free to ask. I'm more than satisfied with this subwoofer, I can help anyone if you need help with the install.