Any tricks to keep cats away from speaker grills?

Sound from the bishop's HT room:

GRITCH... GRITCH... GRITCH... (longer pause)... K'CHIC... K'CHIC... KCHIC... WHUMP!!... RANNHHHHHHH... &(*&(#$&%

Translation:
GRITCH = kitty claws being sharpened on full-length grill cloth of Paradigm Studio 100s.
K'CHIC = kitty claws detaching from grill cloth as kitty ascends grill.
WHUMP = grill detaching from speaker and falling on top of kitty.
RANNHHHHHH = kitty expressing outrage.
&(*&(#$&% = bishop employing colorful metaphor.

Kitty does not enter bishop's music listening room, ever, ever, ever. Six mousetraps concealed under several sheets of newspaper for a week assured this. Only minimal surveillance is now required. Kitty thinks that an evil god lives in the music room. Kitty is right.

Note: If you use the spray designed to repel cats, be sure to remove the grills and let them dry thoroughly after you spray them. Repellant and/or propellant could be bad for cones/surrounds.

Sincerely yours,
Alice
(Bishop's kitty, whose full name is "Chinese Food You Haven't Eaten Yet")

i like the idea of the shock method, but i was thinking more along the lines of disconecting the dryer outlet ever so carefully, and by all means DO NOT FORGET, what you did. watch the cat approach with a video camera. i think it will be simalar to what happened in the movie christmas vacation. send me a video as well, i will show it to the neighborhood cat owners so the next time one crawls on my car the will see what can happen.if you do decide to take ezmeraldalls idea please let me know so i do not bid on your speakers.

I have two ornery little monsters. My solutions (note that I have multiple solutions as not every trick works 100% of the time):
1) Listening room has been walled off and a door is the only entry. This works 100% of the time when I am not at home.
The following are for when I am in the listening room and the cats have access because the door is open. If they stray too close to the audio equipment I do the following:
2) Spray bottle of water. At the precise moment the sprayed water hits the cat I yell NO!.
3) Yelling NO! And chasing the cat out of the room or picking them up and removing them myself.
4) Put a few coins into an empty pop can and seal it with tape. As silently as I can I toss it in the air as the cat get too close to the audio equipment. The loud crash next to them usually sends them running. If I toss it silently then they don't know it is me doing the punishing and the event turns into an "act of God"
5) Give them listening chairs of their own and reward them with affection when they come in to the listen room and hop right into the chair without "checking out" the equipment first.
6) Give them plenty of scratching posts and toys else where in the house. Good catnip is a diversion that will last for hours.
7) Be consistent. Be consistent. Be consistent.

Good luck.