Turntable platforms

The springs should not be damped. Damping hurts isolation effectiveness and it’s audible. You just place the springs under the component. Voila! 🤗 My springs provide vertical isolation, some rotational isolation. LIGO uses many types of isolation including dual-layer heavy mass-on-spring systems and sapphire thread suspension. LIGO pendulums provide isolation in many directions. My first design was a pendulum with very heavy suspended mass that isolated in 6 directions with Fr as low as 0.5 Hz (vertical 🔝).

Undamped springs will ring. If the frequency's low enough it may not be a problem, but the ideal is to damp critically. 

I can't see any downside if damping is an option. It may be impractical to damp a pendulum. 

6 directions? Don't you mean 3?

How did you achieve 0.5hz vertical? 

If you’re so smart why ask me? 

I recently demoed my unsuspended, 70 lb turntable on an HRS S1 platform and really liked what it did.  Better clarity, bass extension and micro detail retrieval.  Just swapped it out for a vibraplane for similar good sonic result with a bonus of zero footfall transmission which makes me think it may be even more effective than the HRS shelf. System is on a suspended hardwood floor.