The VBT (aka TBI) Magellan VIII is another good option that meets your criteria. Very tuneful bass that doesn't get in the way, and has a small visual impact.
I'd recommend a pair if you can swing it, and place them in the corners. I believe they have powered ones but I used a separate bass amp (with my Tact crossover).
I eventually replaced them with RBH subs (also very good, but fairly imposing visually) because I wanted to move more air and set the crossover higher. The VBTs however, were a bit quicker and more tuneful.
IMHO, stereo subs is the way to go, with a separate amp using speaker level inputs (an amp vibrating in a sub box--not a great idea).
I'd recommend a pair if you can swing it, and place them in the corners. I believe they have powered ones but I used a separate bass amp (with my Tact crossover).
I eventually replaced them with RBH subs (also very good, but fairly imposing visually) because I wanted to move more air and set the crossover higher. The VBTs however, were a bit quicker and more tuneful.
IMHO, stereo subs is the way to go, with a separate amp using speaker level inputs (an amp vibrating in a sub box--not a great idea).