best value compact sub

I'm quite intrested in this aswell, I'm not sure weather to upgrade the speaker or get a small compact sub.
I did find somone who will build a box or your sub so it matches the boot and they look good.
 
Under seat subs are awful very poor sound.

Rather than loose my boot space I went for decent components up front (amped).

Did away with the standard rears and built an acoustic shelf,fitted good quality 6*9 in it and used the spare amp channels for these. Use them purely for bass notes.

Sounds better than an under seat anyway,car audio centre fitted and tested various options till I found what worked for me.. I know this doesn't really give you an answer,just trying to steer you away from the under seat things as they are really poor.
 
Subs are all about air mass, woofer surface area and extrusion, supplemented sometimes by ports depending on what you want to achieve.

So underseat/compact subs just won't do the job. Sadly you need a slightly pikey box or just admit defeat that cars don't equal good music reproduction :tongueout:
 
Totally agree which is why I went for a compromise rather than lose my boot.

Besides the last time I had a sub,it attracted enough attention that someone broke in the car to get it.
 
Under seat subs are fine as long as you don't go expecting car shaking bass.

The best thing about them is that they allow you to take the bass away from the doors so there's no rattling. I have a cheapish Kenwood one. I'd buy one again definitely.