Craig, maybe I am not thinking this through well, but what my thought was is that isolating the part to reduce the noise might be different from the idea that certain frequencies may not even be present due to absorption vs. being masked. Sort of like coatings applied to reflective materials to absorb radar so that it doesn't bounce back.

If the platter is 'hooking up' with the base of the turntable due to coupling, these certain frequencies are being drawn down into the base vs. freely passing to the diamond. Not sure if I am making any sense. But I am also not sure if this is different from inherent noise masking.

I am trying to think of this in a similar fashion to the "noise floor" of a radio receiver. If the noise floor is greatly reduced, you can hear weak signals which otherwise do not appear to be there. The signal is there, you just cannot hear it over the noise. But what if that signal was sucked up by something like a change in propagation. It's still out there broadcasting, but its being diverted by atmospheric conditions; and even if the receiver is maximized for an extremely low noise floor, you cannot hear it.

Maybe we are saying the same thing in different terms.

Slim