What subwoofer to choose for 2 ch and HT combined

I myself would recommend a UFW 12 sub with R-DES digital equalization from AV123.com. They have a fast, and musical bass response, and the controls on the back of these units allow for a high degree of flexibility. The R-DES is basically a room correction system for your sub, allowing you to really flatten the fr of the sub in your room.

Link: http://www.av123.com/products_product.php?section=subwoofers&product=8.1

I would also invest in a decent set of sub cables that are able to deliver fast, solid bass.

Thanks very much for the responses. Will definitely check out the UFW and aerial. Have already heard good things about the Vandersteen although I understand they have a "music" model and a "HT" model. Anyone with experience in both, i'd appreciate your opinion on those.

TweekGeek, I agree with your comment about cables. I run DH Labs and JPS everywhere else but have a cheap cable for my current sub (a $500 Jamo sub that's about 8 yrs old). I need to run about 15 feet. Any suggestions without spending huge money?

FLrnlamb asked for more details on my room. Room dimensions are 15.5 x 17 with the longer distance being my viewing and listening direction (ie speakers face down the 17 foot stretch). Carpetted floor, ceiling start at 8ft and climb to about 9.5 however its not a true cathedral in that it raises then flattens out at 9.5ft. Room is on a second floor but the floor is build with a silent sub-floor. I have the flexibility to place a sub(s) in front, right side or rear. Currently have my old sub in front.

I am also keenly interested in learning about good subs for music 1st and HT 2nd. I too have heard good things about James, REL, Velodyne, and Martin Logan subs.

Something else to look at is using Velodyne's SMS-1 to help tune a sub. The SMS-1 seems to be a great tool for integrating the sub to your mains as well as the room itself.

BTW, does anyone have experience with SVS subs? How do they compare to any others mentioned...particularly for music?

I auditioned REL, Martin-Logan, Polk, B&W, etc. and decided on one I never heard before: ACI Titan. After reading so many positive reviews I took a chance and ordered one. (They are returnable if not satisfied.) I think it is the best sounding (most musical) sub of them all. Build and sound are top-notch quality. And Mike Dzurko (owner of ACI) is a top-notch audio guy. Check them out at:
http://www.audioc.com/speakers1/titan/titan.htm
You will NOT be disappointed.
Here is a picture of mine (rose walnut wood):
http://cgim.audiogon.com/cgi-bin/vs.pl?vstrt&1133881069&viewitem&o4

I'll second the ACI subs
But for the extra HT kick I would go with the Maestro (15" sealed), it's what I use and works very well for music and HT.

From the website: Building on the legendary musicality of the Titan and Force subs, we are proud to bring you the Maestro!

For years, our customers asked us for this sub. A sub that can be just plain scary in a high performance home theater. Enter the Maestro: This powerhouse has all the musicality as the Titan and Force, but with a real attitude. The Maestro has an acoustical output at 18Hz that is equivalent to almost four Titans.