@jjss49 wrote: "sure sub swarms of 3-4-5 subs work well, but in the op’s 11x13 room it might just be overkill..."
Multiple subs might very well be impractical in this case because of space constraints, or cost, or for other reasons. But assuming they’re affordable and the individual subs are small enough to be practical, there’s a somewhat counter-intuitive consideration that arguably comes into play:
The smaller the room, the worse the room-induced peak-and-dip pattern in the bass region. And therefore, the smaller the room, the more room for improvement from the greater in-room smoothness of an intelligently-distributed multi-sub system.
Audiophile ingenuity can often find a way where there seems to be none. I have a customer who was in an even smaller room, and the issue was, how to shoehorn four small (but not tiny) subs into his very limited space. Then he read my setup guidelines, wherein I said something like "bonus points if you can elevate one of the subs so that it’s closer to the ceiling than to the floor." He very creatively asked me if more than one sub could be placed up near the ceiling. Yes! So he ended up with three subs atop shelves in his small room, and the fourth one on the floor.
Duke