When I moved into my current place I bought a used Klipsch KSW10. It's been a pretty good sub but lately I'm just craving something better. Did some reading on here and am coming to the conclusion that the BIC H100, PA120, or VK12 are a nice upgrade along with the Cadence CSX-15 and Elemental A2-300.
The BIC stuff can be had for $300 or less on eBay, which is a bargain in my mind. I guess I'm a bit leary on these "unknown" brands, but maybe I'm just out of touch with that super low-production niche.
Anyone care to comment? The room is about 15x18 w/10ft ceilings, hardwood floors.
The rest of the system, if you care:
Polk R50 (f)
Polk CS10 (c)
Polk R15 (r)
Marantz AVR & monoblocks + MartinLogan Motion 3.1 setup