The guys who have $2000-$3000 microscope isolation tables (first reported on in TAS about twenty years ago, now made by Newport, MinusK, and others) have them only under their turntables. One under every component in a system would be a whole lotta dough, as well overkill imo. The suspension of a turntable seriously affects the sound of LP’s, and a serious isolation table for them is justified.
Geoff is again correct (and correct in correcting me!) in the matter of affected frequencies. I used a 5Hz figure for seismic activity only because it is vibrations below that frequency that cannot be provided isolation from except by herculean effort. Spikes and cones are effective down to maybe 10Hz, Sorbothane and Navcom about the same (see the chart on the Townshend Audio site for exact figures).
Roller bearing devices provide isolation down to about 5Hz in the horizontal/lateral plane, but coupling (the exact opposite of isolation) in the vertical. Audiophile recording engineer Barry Diament (from whom I learned of the bearings) postulates that vibration travels largely across the surface of the floor (the lateral plane), and roller bearing are very effective at isolation in that plane. But vibrations also travel vertically, and roller bearings act as couplers in that plane. The combination of roller bearings and either metal or air springs (which decouple in the vertical plane, providing isolation) provide isolation in all three axis down to perhaps 3Hz, about as good as you can do outside of the $2000-$3000 Newport and MinusK tables, and the Townshend Seismic Pods at about half that. I’ll let Geoff speak in behalf of his own springs!
Barry uses roller bearings of his own design (manufactured locally for him only for his own use, not for sale) under his Maggie 3.7 speakers, and both the bearings and air springs (an under-inflated inner tube between two pieces marble or granite, I believe) under every piece of his recording and playback electronics.
