Springs under turntable

This concept of "zero stiffness" is interesting.  I have been reading the paper that was cited above.  It seems in fact to be a theoretical ideal rather than a truly attainable state. But that's OK as a guide. From my experience with turntable supports, the Minus K comes closest to zero stiffness.  If you can achieve what the Minus K achieves using only inexpensive commercially available springs or modified springs, you are a very patient person.  I would still have more than reservations about seating a speaker on a support that had zero stiffness, especially in the horizontal plane.

UPDATE on my nobsound springs adjustment...

The adjustment by adding load is more delicate than i said at first ...

A difference of 2 pounds of load, not 4 pounds, on around 90 pounds of load in total, make a substantial difference in the high frequencies mostly but also all across the spectrum...

A little more than 1% variation in the load is critical....

Keeping off a number of springs from the 7 in the 4 boxes on each speakers would be a too much gross adjustement.... I prefer then with my speakers varying the damping slabs of concrete....For the last tweaking of the load i use 2 plaster book-end on each speakers because they weigh half the weight of a brick, around 2 pounds...

I think that would be very delicate for a turntable, because it is delicate and had take some listening time for my speakers....

One thing is sure, those that think mechanical embeddings makes a not so great difference, and are only an accidental secondary "tweak" would be surprized....

A "tweak" is only a minor addition, a minor refinement when it work; controlling the embeddings is not minor addition, it is a transformative major action on any audio system, be it mechanical, or electrical or acoustical....I am not interested by accidental "tweak" so much, i am interested by the method and the ways to embed the audio system and his parts.....

I forget to say that refining the load around 1 % affect the frequencies so much that it is audible on the instrument timbre expression... I was listening violins when i discover that i was with 2 pounds overweight.... Adjusting it was spectacular in the sense that suddenly all timbre expression become more natural....

:)

Then pay much attention to the load or the number of springs or the design of the springs itself especially for a turntable but anyway for any applications.... The taking off springs will be too gross ajustement for most turntables...

I think that other springs will be better for most turntable, depending of their weight in relation to the springs diameter, turns, mass etc....
These springs can be very good with one turntable because of their measures numbers and size and numbers possible adjustment, and not so much with another turntable.... People must be conscious of this...

Springs adjustment to the load to isolate in relation to frequencies is really something necessary to compute....

It is more easy with a varying load on speakers to compute with the ears, than with a turntable and only the 7 varying number of springs to play with....

:)

We will need rixthetrick.... :)

But i dont have a turntable....:)

Adding 6 Nob loose springs under the six tube phono amp brought improved clarity, musicality, vocal diction, speed and dimensional perception of instruments in the soundstage. BUT it reduced bass weight and enhanced upper mids to the point of coloration. I replaced the loose springs with 4 aluminum cones which brought things back. Bass returned but the improvements noted above faded. (The turntable is on springs.) Disappointed to lose the amazing clarity but frequency balance better. So it appears the phono prefers stability.

@lewm - yes.

RixTheTrick 09-05-2020 11:29am
Zero Stiffness is an ideal.

I have mentioned Minus K in Agon before, and I am on their email list.
They are very expensive. Their upright flexible pillars are an excellent means of controlling horizontal plane movement - a truly excellent product.

I also have reservations about seating speakers on close to zero stiffness systems. And I have many times stated that broadening the base to accommodate the instability created by spring isolation is essential on tall loudspeakers with a narrow base. I have springs under my subwoofer with absolutely no issues.

I have also suggested mass loading under turntables on top of springs as well.

I would also suggest that for loudspeakers anything over 10Hz should be isolated, and a plynth for a turntable I think if I recall correctly 4-5Hz on a mass loaded plinth.

@frogman
I’ve been stating for sometime now that what you put your isolation system on is equally as important as the design of the isolation system.
If you don’t mind, what was the VPI HW19 MK4 with springs supported by?
What was under it please?