I wonder if you got some plastic mesh (google on "Deer Fencing"), about 1"-square, and put it on the front side of your Maggies, PLUS got the scratching post mentioned above, whether that would do the trick. Rub some cat nip on the post. The deer fencing is black, so it may not even be noticeable. Get it at a mesh size and toughness that the cats will not like. Use plastic rather than metal - I'd guess - due tot he magnets in the Maggies? Anyhow, after a while, once the cats prefer the post, you may be able to remove it entirely.
alternative to maggies?
help - i have & love my maggie 3 series speakers - but i have a cat problem & have read & tried to resolve it various ways. if i must search for an alternative speaker to satisfy me like my maggies & you also love the maggies what speakers costing no more should i try to listen to to satisfy the beauty of something that otherwise don't need fixing? i listen mainly to rock & jazz. i don't just want speakers which sound really good but that sound really good = lively airy spacious etc compared in the same room as maggie 3.5, 3.6 or 3.7's.