Springs under turntable

Noromance, If it is bouncing less than three times a second you are fine. You can use the same springs all round but you have to locate the center of mass and place them equidistant from that point unfortunately a tricky thing to do. If you use springs of unequal rates and they do not bounce at the same speed you can create an unstable situation. Correct, in this type of situation it is difficult to hand Q the record. This is one resaon the SOTA tables are so nice. The hung suspension is inside the plinth so you can put a hand down on it. you can even rap the plinth with a hammer no problem. Designs like the SME you have to use the Q device. 
If you think this sounds better you may want to consider a carefully engineered product like the MinusK stand or the SOTA turntable. 
Many of us know for a fact it sounds better including Michael Fremer who puts his $100K turntable on a MinusK stand. he designer of that turntable now has a MinusK stand built into his turntables!

i dont own a turntable...

But i know first hand how vibrations can kill sound...

My speakers are on my desk and all my other gear parts...

My "sandwiches" of different materials were good (quartz/granite/ bamboo/ sorbothane/ cork) but not enough it seems, adding springs under the speakers(i keep the sandwiches under the spring tough, makes an audible clarity increased...

A turntable is so sensible, like a little seismograph, than imagining driving it without special precautions against vibrations is illusory and vouching for disaster S.Q.

+1 indranilsen - Solid-tech & Townshend were pioneers, and are now being copied, probably cheap Chinese knock offs.

Next level is AMG toppers, or similar technology TMD dampers for the cabinets, in conjunction with isolation for speakers.

My next big thing is quasi-zero stiffness on my stand mounts.
There's no real shortcut here, it's going to require engineering and more math study to get this correct, and look pretty.

My previous employer has used isolation under turntables for over 30 years, and still manufactures mass loaded shelves with springs.
Happy experimenting, I am enjoying the sounds too!

I bought those springs months ago. I put them under my TT and did not hear any significant difference. I did notice my TT became a little unstable and would skip if I accidentally bumped into my cabinet. Since I owned them at this point, I experimented and tried them on other equipment. My only noticeable difference was on my sub woofer, everything seemed a little clearer and the bass is tighter. That's where I left them.

Interesting discussion on damping and isolation.

I am going to buy some Nobusound springs to experiment with on some components 

Currently my Garrard 301 plinth is on Nordost SortFut footers and sits on a Vibraplane. The combination of the SortFut draining mechanical vibration from the turntable into the massive Vibraplane combined with external vibration isolation from the Vibraplane, results in a great presentation.

The Vibraplane is on a heavy wooden rack which sits on engineered wood over concrete foundation