The caps you put over the claws are called "soft paws". They work but are a pain to put on a cat because you have to restrain a cat and glue caps to it's nails. Sound fun? Also, if they dont all fall off it can can be dangerous to the cat as the nail will keep growing and curl into the pad and trap the cap in between. It happened to our cat so you just have to keep your eye out. Another option is double stick tape, they sell it at pet stores to keep cats away from furniture corners etc. It's a very thin 1.5-2" wide tape and cats hate it. Supposedly it trains your cat to not scratch the areas it is applied to but it looks fugly because it's tape after all. The suggestion to remove the grills all together seems like a good option also and perhaps the best if possible. Fortunately for them, our cats have never touched my speakers so yours may do the same. Other than that just make sure you have a scratcher or scratching post they can use and put cat nip on the scratcher to get them attracted to it. Hope that helps!
