Springs under turntable

Chuck, added bunch of springs under the phono. Info overload!!

Goners know I am a big fan of suspended turntables. I will never own anything else. There are two big issues. First, the resonance frequency has to be below 3 Hz both vertical and horizontal. If you get to close to the tonearm’s resonance frequency fun things will happen. Next, a mass placed on top of a spring is unstable. Not only will it bounce vertically but it will wobble side to side and if the mass is large enough it will fall right over. This tends to be the case when you get the resonance frequency low where it should be. When you hang a mass from a spring the pull of gravity always returns the mass to vertical, a much more stable situation. So, the best way to do this is too hang a platform from three or four springs and place the turntable on the platform. Or, you could buy a MinusK platform or you could buy a SOTA, SME or Dohmann turntable. Isolation is critical for turntables and a properly sprung turntable is much quieter and impervious to almost anything. You should be able to hammer on or kick your equipment stand and not hear a thing. All of the above tables will do this and if you are clever you can get the same results. You can dampen the springs by inserting foam rubber into them.

I am new to decoupling and springs in the past two weeks and have been very pleased with the results compared to spikes on a concrete floor.  I have noticed similar sonic improvements as those you have listed.
I considered the spring device you are using and opted for single springs under the corners of my amps and speakers.  I will also be using them under my subs soon.  For me, the single springs work great with the key being to determine the right combination of diameter for stability, total load capacity per spring, rate of compression for the desired stiffness, and finally the compressed height that is appropriate for the equipment or speaker being supported.
I had good luck finding what I needed from Century Spring Company, that has an interactive specification tool to help you find the appropriate springs.  One other thing you can try if using single springs is to encase them in heat shrink overlapped at the top, which not only hides the springs but also provides a bit of protection against scratches for both the gear being supported and whatever you are supporting it on.  If you believe air needs to escape from inside the spring, simply poke a hole in the heat shrink.

Thanks for the replies. I did some more critical listening. Some notes below.

• Lots more detail - I can hear more of the acoustic, inner detail, deeper stage.
• Tiny details more obvious - like listening to records all over again
• Speakers are totally GONE
• Cleaner but lighter bass - reduced bass?
• Volume needs to be set higher - not as loud - this is weird.
• Brighter - maybe a little too bright - not unpleasant - makes the 401 idler sound more like a suspended - I also have an LP12.

More later when I can get away from desk.

@mijostyn It is bouncy - I have to use the arm lift. But it settles in about 1.5 seconds. The plinth/401 is heavy. I can't use the same type of spring as the weight distribution is not equal.
I am only going by "does it sound better or worse?"