Sota Sapphire and Isolation?

Soix, you do want the SOTA on a solid support, which is the road bed in my analogy. Perhaps think of a spring suspension that bounces at 2 cps. Now mount it on a spring suspended shelf that bounces at any different frequency. Can you see that the two suspensions will interact negatively? At some frequency the TT will be disturbed to a greater degree than if there’s only one suspension by energy coming from below the bottom suspension..

I owned a SOTA Sapphire from the early 80’s, purchased new from the factory when it was still in downtown Oakland, CA by the Coliseum.   Nothing short of nuclear testing in the room would cause an audible issue.   That is a fabulous table.   I can’t speak for the current version, but I’d experiment with what you’ve got.   I wouldn’t be surprised to find that adding additional isolations does not help.

good luck and remember to just enjoy the music.

I use a wall mount and that cured any issue 

Thorens makes an isolation pad made with layers of some kind of foam.  Check it out, it's only a couple hundred bucks.

I have a non suspended SOTA and it seems immune to footfalls and rumble….   The Sapphire should be well isolated from subsonic stuff.   Enjoy