Sub(s) ideas to match Salk Silk Monitors

Looking to pair Salk Silk Monitors with a sub or a pair of subs...smallish room, 13'x19' Can I get away with a single sub or do I set up a pair? Not opposed to used subs, budget $1200
1. I would ask Jim for his thoughts.
2. I would ask for advice on the Salk Sound forum at Audio Circle.

PS: How do you like the Silk monitors?
Jim Salk has speaker models into which he installsĀ a Rythmik Servo-Feedback 12" or 15" sub, and he also builds custom cabinets for Rythmik subs. I would imagine any Salk speaker would benefit from a pair (two is always better then one, no matter the size of the room. In fact, the smaller the room, the more of a benefit is the second) of Rythmiks. Head over to the Rythmik site, and check them out. You can get a pair of 12"ers for $1200, I believe.