I think buro9's recommendation is pretty sound. I have some smaller/older/cheaper KEF speakers on my desk, where I don't have the space to put the larger PMC speakers I would normally use. They have a dual-concentric design that is clearly related to that of the LSX and LS50, and (at the risk of "dancing about architecture") I've been very impressed with the clarity and directness of the sound.

On the basis of that experience, I'd certainly have the LSX/LS50 on my shortlist if I was looking for speakers in that size.