I’ll second the no declawing comments. We tried this with one cat years ago (not proud of it) and he turned into a very badly behaved cat that had to stay indoors and he still managed to trash my speaker grills with his back claws (serves me right). Cruel and would never do this again.
Also, despite advice from many vets we also allow our cats to go outside. Their behavior also improved when allowed to come and go at will through a cat door. Yes it’s a bit more dangerous depending on where you live, but these critters want some fresh air and to chase rabbits (sorry Al) and birds.
Not to start a war about it here, but I’d never declaw a cat. There are strong opinions on both sides. To be clear though, I fall on the side of compassion and care.
+1 emphasis on non fabric.
Our last cat ignored the scratching post positioned right next to the sofa and loveseat that she shredded over her many years. And she wasn’t content to limit her attention to one part of either. Shred and move onto the next. Tape, sprays, and any other deterrents were ineffective.
The only training devices we found effective in discouraging other behaviors were a squirt gun and a soda can rattle - a few coins in a can.
Honestly, same here. I’ve had 4 cats in my life including one kitten years ago and none were interested in hi-fi beyond the warmth of the gear, which I have in a vented cabinet now.
Best way to keep cats from destroying your house is to not let them in.
I said the same thing about children, the I had one. He’s 30 now. House is fine. Hahahahaha
Yeah, It’s easy to object to destructive “guests” a priori. But not so easy to deny their worth once you invite them in 
Had … Maggie 3.6 speakers… it only took once to turn the “indoor” cat into a mostly outdoor cat.
I made an outside scratching post which the cat liked… if you have never had to re-sock a Magnepan speaker… youre a lucky person… a ton of staples were needed to remove and replace on the bottom of the speaker… although some have said their cats have never attacked their stereo system, “It only takes once”… for speakers, the thought did cross my mind to encircle the speakers with a “small cage of fencing 1/2” material… but as the cat moved outside, that project never came to fruition… good luck w the new felines…