As I detailed in my long turntable isolation shelf construction thread:
I tried tons of materials, pucks, sorbothane, woods, you name it, including Townsend Seismic Pods, to see which would produce the most isolation from exterior mechanical vibrations. I used seismometer apps to measure and record vibrations. Nothing else came even close to the objectively observable effect of the Townsend spring based pods, placed underneath the turntable shelf. Stomping on the floor without the pods, I could feel with my hand and measure large ringing spikes of vibration on the shelf. Once the pods were put under the shelf, I could stomp the floor (sprung wood floors) and feel nothing with my hand on the shelf, and measure almost no vibrations getting through!
I have no idea if this in fact contributed anything to the sound quality of my set up (my turntable is in a different room than the listening room).But it sure is useful insofar as I have a son who walks around like Godzilla, and who used to skip my records just passing by my turntable (doesn’t happen any more).
I actually, for the heck of it, ended up throwing a bunch of materials together since I had them. So my Transrotor turntable sits on a 2 1/2" thick maple block, then a sheet of 1/4" steel below that, then two layers of MDF, different thicknesses, bonded together by wall-sound-damping material, and then all that held upon the Townsend pods.