what to do with my cat on my speaker grills

A less cruel way is to Pick up a can of Orange Citrus Spray at Bed Bath and beyond or that type of store
shoot a few seconds of orange spray into a plastic sandwich baggie.
place under or in back of the speaker the opened bag should act as a deterrent as they don't like the citrus smell.
Good Luck Johnnyr

Double stick tape perimeter

Pellet gun...

Place a large dog in front of the speaker. Cats hate woofers!

I make protective boxes out of foamboard, with only the top, sides, & front, to go over all my speakers. no back or bottom, so they just slide over them to protect.