I went through a similar process when trying to select a sub. I am focused on music much more than movies. Based on the reviews and some recommendations, I decided to go with two subs although I have only purchased one. The other will come in a few weeks. There where three combos I liked. HSU ULS-15s, SVS SB12-NSDs and Power Sound Audio XS-15s. I think I would be happy with any of these options. I decided on the
Power Sound Audio XS-15s. After reading the reviews on the XS-15 ($750.00ea with a discount for 2). I felt it would blend better for my music needs. I'm going to post my detailed review (fwiw) once I have it tuned in a little better.
My first impression of a single XS-15 after 10 hours of light use:
1. VERY well built.
2. Easy to connect and set up.
3.
Music sounds amazing and will only get better with tuning and placement (and the second sub).
4. Movies (Pacific Rim) sound great. I'm sure there are better subs for movies but this sub rumbled when it needed too.
5. I have to turn up the gain more than I would like but I think that will change with tuning and placement.
6. I'm not sure I even need the second sub because this sub fills the room really well. OK I still want the second sub.
My room is only 1600 sq ft so your needs to fill that room may be different But I think a two sub setup would fill your room with out any problems.
I hope this helps!