Subwoofer Question

I currently have a Martin Logan Balanced Force 210 sub paired with Dynaudio Contour 3.4 LE speakers and a Prima Luna HP Dialogue integrated amp.  My listening space is fairly small (listening position is about 11 feet from the speakers.  The nature of the room only allows me to place a sub in the front corners of the room near the speakers so I can really only have two subs.  I have been toying with the idea of selling the ML and replacing it with dual subs, one in each front corner.  One particular sub I have been thinking and reading about is the REL t9i.  Why am I thinking about this? No other reason than the itch to tweak but certainly also to improve.

I would greatly appreciate this board’s thoughts and insights.

Thanks,

puppyt