spring loaded platform non-suspended turntable

Crubio, I'm not an engineer but I'll suggest you need to consider three conditions. One is acoustic vibration from your listening room environment. For example, where is your turntable placed relative to room node build-ups? Hint: avoid placement in any corner, bass range build-up is greatest in those.

Next are the mechanical vibrations generated by the table itself. Slate has a good reputation for absorbing (draining) low frequency vibrations so that, along with your 100 pound mass, should do well in minimizing this problem.

Last are the external mechanical vibrations which can affect your turntable/arm/cartridge performance. This will vary from set up to set up. Do you live near a street/highway with heavy traffic? What is the construction of your floor? What kind of stand is your table mounted on? Is it mounted on a shelf attached to a load-bearing wall?

Depending on your conditions, adding any sort of suspension may or may not improve your listening. If you could find a modestly priced suspension system (inflated tube or bladder) to try for comparison against what I assume is your current non-suspended mounting, that should indicate if it would be worthwhile to then explore suspension options.

Sorry, there is no simple answer to your question.

Stringreen, I respect your musical knowledge and experience, but I believe you are wrong about "acoustic feedback". My simple understanding is that it is the airborne (i.e. acoustic) waves from output back to input. The most common example most of us have heard is an improperly set up microphone in a auditorium which howls from the sonic loop from PA speaker back to the mic.

Similarly, a turntable/arm/cartridge system is subject to the sonic energy, particularly low frequency tones, from the speakers. Wall mounting will only be effective if it moves the tt system away from a bass node loading area. It is not related to a springy floor. In extreme cases I've seen the tt system placed in a separate room from the speakers to minimize acoustic feedback. Fortunately most of us don't need to go that far.

This is why I suggested consideration of all three conditions for unwanted energy in my post above.

"remember too that sound travels as well through springy floors (and walls)"

Absolutely, but my point is once the sound wave strikes/energizes a solid surface/object, the transmission then becomes mechanical, no longer acoustical. I consider acoustical to mean through the air.

In this view, sound waves do not pass through walls and windows directly. Coming from their source they strike a solid surface (drywall or glass in this case) where the energy is transferred by mechanical means. Some level of sound is reflected back, while some frequencies are filtered out (dissipated) in this process which is why higher pitched sounds may not survive. That transferred mechanical energy which survives then excites (vibrates) the air on the other side of the wall or window where it becomes acoustic again.

Consider the transformations with your violin. You pull the bow across a string which creates a mechanical resonance. If someone stands close enough to you they may hear the acoustic transmission of that string vibration, although it will be at a very low level. But the string vibrates the bridge as well as the air, which transmits energy to the soundboard (top of your instrument), which then vibrates air within the cavity of your instrument which becomes amplified by resonant reinforcement and comes out the f holes as acoustic sound waves which can now be heard from a much greater distance. (And yes, some acoustic sound is also projected out from the soundboard itself.) All this involves two different types of energy transfer.

I'm not trying to split hairs here and I don't pretend to understand this as well as a trained engineer or physicist. But I do believe if we are to address a problem it serves us to understand the causes as best as we can. This is why I break down vibration issues for turntables into three separate sources - acoustic, internal mechanical, and external mechanical.