I'd be thinking M60s or M80s, and just leave the grill cloth off. If it becomes a problem, you can always try it with the covers on, but I think that would be more tempting to a cat.

The M50s could be an option as was mentioned, but they'll have a slightly different sound than most of the Axiom lineup. Neither better nor worse in some people's opinions...just different. (Others will argue that the M80s are just better than anything! smile

::::::: No disrespect to Axiom, but my favorite woofer is my yellow lab :::::::