Nobosound Springs

I am a big believer in spring isolation.  I have nobosound under my amp and DAC.  I don't think gains are huge isolating your components when your floor is concrete.  There isn't much vibration getting transmitted. But it can't hurt.  I will point out that the standard nobosound has 7 springs.  You should probably reduce it to 3 for your turntable.  This will adjust the natural frequency of the spring system (calculated as sqrt [k/m]) badk to where it sould be.  Since the m of your turntable is low, you need to reduce the spring constant k, and less spings means lower k.  That is unless you've got one of those huge massive turntables (I'm all digital so I've never picked up a high end turntable).

On my 140 lb speakers I decided the nobosound were not stiff enough and went with a professionally designed spring isolation system from townshend.  I too was shocked by the improvement.  It was about $1600 more than nobosound and sounds like the results were not much different than you achieved but it does have a stable platform and an engineering calc behind it.  

You might post the weight of your speakers.  You have experimentally determined the mass of a speaker that matches the nobosounds well.

Jerry

Instead of buying a bunch of shoes, I  try inexpensive iso/vib devices. I have 4 sets that I will sell for $15/set 4 + shipping

Anyone balking at expensive isolation might try these to start out and then upgrade if the itch isn't yet fully scratched. 

I'll take isolation devices over springs every time as the premise seems flawed. I do like the term nob o' sound though.

Are those cork pads better than the nob o springs? I have some nob o springs and I hot glued the springs in on one side so they can't fall out when moving gear. I only use them on lite gear. I have some Townsend springs but no good under my table. It's to heavy.