Hello,
Cats really dislike aluminum foil and sticky stuff. You can use it to deter the cat from getting on top of the speakers or around them. The real issue is keeping them clean. See if you can figure out how to clean them. Also, I would add a hepa air filter in the room. You might have to turn it off while listening but it will cleanse the room while music is not in use. Also, Another wired one. Put fly tach strips or double stick tape near the speaker. It will grab and hold everything. Good luck.