Sound Addicted Subble 1.2'' (4 Pack) Silicone Feet Isolation for Amplifiers, Decks or Any Other Audio Equipment, Non-Skid Hemisphere with Adhesive (Sustain up to 24lb) | Subble

I really depends whether you're trying to solve a particular issue such a foot-fall. I do not know what the bottom of that deck looks like but I used these on my Dual as a generic foot replacement/improvement over the worn out factory felt: https://www.amazon.com/dp/B08FD8TRPD Sorbothane is better but more expensive: https://www.amazon.com/dp/B00AJ1PI66 For my PS-4750 after I repaired the perished rubber in the originals with 3D printed TPU I made some extra feet that sit under the factory feet, they're made from Sorbothane discs: https://www.amazon.com/dp/B07MWBVM57 They look like this: That gives the deck a lot of isolation. Total overkill to be honest; it's already on a floating shelf.

OP, you could actually order a pair of these from Parts Express and tack them over the exposed speakers with some silicone adhesive. That's what I would do if I had the F or H model, but I have the D. I would also recommend lifting (de-coupling) the subwoofer off the floor a couple of inches or more which is usually recommended to give a smoother(?) sounding bass. Something like this or foam pads from packing material you might have laying around.