Assuming that you have two cat carriers (used to transport the cats to/from the Vet) try placing one near each speaker.
Our cats shy away from the carriers.
Sticky tape completely covering the floor area around the speakers would seem to be effective (doubt they would leap over it to cling/hang from the socks).
Tin foil may also work, but "some" cats spray/pee it.
I'm currently refurbishing a pair of SMGa's, but due to having 5 cats in the household I doubt that I'll be keeping them (the SMGa's that is).
Someone here (TubeGroover/SwampKiller maybe - I forget) used chicken wire barriers around their speakers. Kind of a cross between "Green Acres" and the "Blues Brothers" if you can handle it.
Currently have vintage floorstanding cabinets in the living room with the cabinets/grills being untouched by the cats in the past two years, but a third/duplicate cabinet, stored in the guest bedroom, has been shown no mercy. Go figure.