I just replaced the front speakers with ImageDynamics NX30's, and the high-end improvement is wonderfull. Now I need to fill in the bottom end. The factory BOSE system is plenty loud enough for me, but lacks the richness and deapth deserved by the music I listen too. As such, I need suggestions on sub, amp, and box design.

I love both Opera and Trance equally. Luckily I don't have to chose between them, since there are a couple of artists combining opera vocals with electronic instrumentals. At the same time, popping Bach in the player and feeling the bass (if you don't listen to Bach, you don't know bass) is an awesome experience as well.

As I said, I don't want my system to be much louder, just to fill in the bottom end.

Thanks in advance for the help.

Infinity makes a powered sub i have in my Landcruiser and in wifes expidition.I think it fills in very nicely.

To be honest, with the type of music you are listening to, you might want to try to remove the 9" speaker from the front door and add a GOOD set of 4.5 or 5" and a set of 6-6.5" woofers. A good 6.5 inch woofer will produce amazing sound for the type of music you mentioned listening to. By adding both the ~5 and ~6 inch speakers, you will have an increadible midrange. You wont have earthshattering bass, but you will have an awesome sounding system.

The mids are quite good now. There is a richness and deapth missing from the bottom end that I want to fill in. Not booming rattle the doors on the cadilac next to you bass, but something approximating a live performance.

Perhaps a single IDQ 10" sub in a medium / small sealed enclosure, fed about 150 watts RMS?