I've had my studio main monitors on sets of IsoAcoustics vibration decouplers for a number of years now and am empirically convinced of their effectiveness in preventing the transfer of mechanical vibration into the surface beneath the speakers.
Using similar vibration isolation for stage amps can also offer useful benefits, and the IsoAcoustics ISO‑L8R series, primarily designed for larger studio monitors, can also be effective with guitar and bass amps. Bass players in particular can be plagued with an uneven response in some venues, particularly those with 'wooden box' staging, as vibration in their speaker cabinets set off unwanted resonances in the stage. The result can be 'hot notes', or 'black holes' where certain pitches just seem to disappear. Guitar amps, with their lighter bottom end, are less prone to mechanical coupling, but stage resonances can still manifest as an annoying sort of coloration. Breaking the direct physical contact between the speaker and the environment with a broadband 'lossy' connection that absorbs rather than transfers energy — the fundamental principle of all the IsoAcoustics designs — makes the issue go away completely.
The recent addition of the Stage 1 Decoupling Amplifier Isolators to IsoAcoustics' stable of products has been followed, logically enough, with the launch of the Stage 1 Board — a 25 x 10–inch lightweight ABS board to which a set of four Stage 1s can be attached. The low-profile design of the Stage 1 feet (only 1.5 inches tall) means they can be screwed directly onto the bottom of combos or cabinets without adding too much height, but if you'd rather not make extra screw holes in your gear, you can now use them with the Stage 1 Board. The isolators and the board are purchased separately, but assembly won't tax even the most 'DIY-challenged'.
Any 'classic design' combo, such as a Fender Twin, Pro or Deluxe will fit perfectly on the Stageboard, and there is just enough depth to fit the feet of a Mesa Mark series combo.
Four Stage 1 decouplers together can support weights up to 200lbs — enough to handle a double 4x12 tube stack, apparently, but of more relevance to most of us, enough to handle a heavy tube combo or bass amp. Any 'classic design' combo, such as a Fender Twin, Pro or Deluxe, will fit perfectly on the Stage 1 Board, and there is just enough depth to fit a Mesa Mark series combo. Both of my bass cabs are a little too deep for both front and back feet to sit on the board, but I understand there will soon be a larger 30 x 14–inch version of the board, more suitable for larger cabinets and bass combos.
Having used a Stage 1 Board on several gigs, for both guitar and bass, I can confirm that it does indeed work exactly as intended. Of course, a decoupling system is a problem-solver — so you've got to have the problem in the first place for it to be of value. But if you're a regular gigging player, sooner or later you are almost certain to come across a venue where your sound would benefit from it.