Too late for GoliverJr cats, but don't declaw them. They probably avoid Stanley because they feel they cannot defend themselves. And how would you like your finger nails pulled out.
If you squirt them with a water pistol or spray bottle when they go near your speakers, they will get the message after a few times. They also won't become fearful of you with that technigue. (Sugarbrie is my pedigree Maine Coon Cat Sugar Britches).