"Cats & Speakers" are a common concern, however as most here have attested a little training goes a long way.
I second the recommendation for regular "pawdicures". Even if the cat isn't used to it, with the aid of a helper and a towel wrapped around the furry one this can be accomplished with relative ease after a bit of practice. There are obvious added benefits to your carpet, drapes etc.!
For a brief while, our feline overlords found the woofer covers on my Linn Ninka's attractive - the metal grill seemed to offer a texture they liked, until squirted

I was most concerned about the exposed woofer on the Gallo Reference 3's, but that was completely ignored. Only my JBL Synthesis sub-woofer's grille fabric has suffered from unwanted attention.
Filling speaker stands with sand and using blu-tack is the best protection from knocks I can think of for stand mounts and the presence of a cat dusting the top of any speaker is highly preferable to someone thoughtlessly using a speaker as a coaster for their cocktail.