Room size for Cornwalls?

This is not a pleasant message to deliver, but I cannot think of a single relatively full range speaker that would sound good in a room of your dimensions. On paper your dimensions equate to a truly problematic room for bass reproduction. If you like the classic Klipsch sound you might try one of the Hersey models.

However, before doing anything you should do some research on room dimensions/room modes.

This is a link to the room mode calculator on the Klipsch website. Enter your room measurements and then as a point of reference enter an 11x12x9 room. If you care about getting good sound the dimensions of your room are important.