I’m not about to argue with whatever one wants to try putting under one’s turntable, but I think there is a "logical" argument against putting springs or anything spongy (e.g., sorbothane) under speakers. The amplifier is putting energy into the speaker drivers. Ideally you want all that energy to be converted into the motion of the drivers, so as to capture the nuances of the music signal as much as that is possible. If the speaker cabinet is sitting on a surface that can move, then inevitably (as in Newton’s Third Law of motion) some of the energy of the signal delivered from the amplifier is converted into motion of the cabinet, rather than into motion of the driver cone. That can’t be a good thing.
An argument that seems logical do not equal an experiment...
Have you ever try sorbothane in the right condition? No more than springs i think, no?
«I can state flatly that heavier than air flying machines are impossible.»
— Lord Kelvin, 1895 one of the greatest scientist of not only his time but of all time also ...
«It is apparent to me that the possibilities of the aeroplane, which two or three years ago were thought to hold the solution to the [flying machine] problem, have been exhausted, and that we must turn elsewhere.»
— Thomas Edison, November 1895 I will not add that i myself use springs under my speakers, and i will not confirm that this is a great increase in clarity... Nothing of the sort, because this is my opinion but after my own experiment indeed...
And someone will come with some concept only looking sound and will contradict reality....
I will keep silent and smile listening music....
«Opinions were for Plato entertaining illusions in a cave, is it not TV ?» -Groucho Marx