Website for subwoofers?

What specific subwoofer?
Most of the time the manufacturer will list what they recommend.

In all, you can technically tune a sealed enclosure.

Yup, I'd first check with the manufacturers site. But you can tune any enclosure. I found this site for some pretty good deals on Subs, I've been throwing them out there on this forum a lot... I'm buying too much stuff maybe ???? Naaaaa :rofl:

Anyway, here's the site: www.sonicelectronix.com

Just get a JL Audio 8w7 or Alpine Type X (for more output). I had both, and I still have the 8w7 in ported enclosure (recommended) powered by a Kicker ZX750.1 @ 3 ohms. Great bass (Not to much) and sound quality balance.