Springs under turntable

The big problem with just two springs is that it's now like a bike, only support on two 180 degree opposed points.
You really need three or four to be stable.
Try supporting your amp with two points.
You get the picture.
Now four pods means yes you can do it but it is very wobbly as I said even with them being compressed.

As for subwoofers the trick is to give the driver a perfectly solid enclosure with an infinite mass. Not so easy. Put your hand on your subwoofer enclosure while playing something bass heavy.

I have a pair of dual voice coil drivers firing opposed in a sealed cabinet (32mm or 1.26" thick MDF), with substantial bracing. The cabinet is not totally inert, however it is pretty decent. Though certainly no contest for my stand mounts with the steel plate lining it, also with cast iron braces, silicone filled hard drawn copper tubes and birch differential bracing. I have exposed the internals in my system page (the stand mounts, not the sub).

Both lifting the sub an inch, and isolating it at approx >4-5Hz makes for significantly less energy to be injected into the floor, the walls, and everything else.
It is an experiment worthy of the almost puny investment.
You may very well be surprised if you were to experience it for yourself?

My two Martin Logan Depth i subs are made '6 sided' with 3 equally opposing 8" drivers, This, as stated above, eliminates almost all internal vibrations. Several months back I put Stillpoints SS feet under each sub directly to my sprung wooden floor and they made a substantial positive difference. I already had these on hand. I plan on trying springs there at some point, in no hurry though.

@uberwaltz  Not springs -pods.

Great work here on tuning these things. Definitely not a case of plop em down and all is well. Have tried half a dozen springs now, plus variations, all were much better in at least some ways but it takes some work to get the most out of them.

Rick did the hard work in the beginning figuring out what to use under the Moabs. He used math and physics but the rest of us can use what indranilsen is doing, seat of the ears, try and see.

The four Nobsound with 4 springs each under my turntable were under Round Things and above granite. Got the wild idea to flip two of them around, so from bottom up its granite, Round Thing, spring, Shelf. Lo and behold there was a nice improvement in midrange presence, treble extension, and a much greater sense of acoustic space!

Went back and sure enough the midrange was ever so slightly less clean and clear. So flipped the two back again. Then flipped a third, and finally a fourth. Was kind of afraid of getting too much top end or too lean bass but this never happened. Hate to say its like magic but it really is.

Maybe one of these younger people will come over and tell me its too much. I don’t know. Pretty sure my old ears top out at 12k, 15 maybe tops. But what I do hear, the ability to hear both the music and the acoustic space its in is just fantastic.

uberwaltz, when using just 2 its much more stable along the long axis between the two than crosswise. Each one by itself is quite wobbly. But try orienting them so they are all pointed to the center. That should be a lot more stable.