Springs under turntable

Spikes vs. Springs
They are obviously selling something but bring up some interesting observations.

https//youtu.be/dW9-r83IvhI

@mijostyn 

For people whose woofer driver carries a substantial amount of the midrange a higher crossover is a large advantage lowering distortion in the midrange. This is typical of two way speakers.

To achieve the reduction in distortion you described would require the main speakers to be crossed over above the low bass frequencies, using something like a high-pass filter, correct?  The benefit occurs by allowing the low frequency driver (especially in a two-way) to mostly operate within its optimal range of excursion without being required to try and reproduce both midrange and lower bass frequencies.  

Certain engineering evaluations can be solved (approximated) by modeling the behavior as a series of springs and dashpots.

@mijostyn 

in that situation the springs are not isolating the speakers or the floor from anything

I am interested - please explain further since the springs would be between the speaker and the floor.

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.

@mahgister 
Many others have also reported sonic improvements when decoupling speakers and the Townshend folks believe springs and air bladders are two of the better decoupling methods, although there are other methods such as using Herbie's products, roller bearings for decoupling in the horizontal plane, etc.  I believe the physics are likely complicated based on the many variables involved with specific applications but regardless, quite a few who have tried decoupling believe they hear improvements including folks like Jim Smith, author of Get Better Sound
https://www.amazon.com/Get-Better-Sound-Jim-Smith/dp/0982080700/ref=sr_1_1?dchild=1&keywords=get+better+sound%2C+jim+smith&qid=1599172058&s=books&sr=1-1

@mahgister 
I suspect variables related to the success of decoupling speakers include the floor (i.e., concrete or suspended wood), the weight of the speakers, the stiffness and resonant frequency of the speaker box, the force generated by the drivers (i.e., larger woofers create more back pressure than smaller midrange or mid-woofer drivers), whether the speaker design is acoustic suspension or bass reflex, if and how the speakers are mounted on stands, the weight distribution of the speakers (i.e., heavier in the front?), and other variables.
I suspect factors affecting the decoupling medium include stiffness, number of coils, and degree of compression (if using springs), pressure, volume, and elasticity (if using an air bladder), hardness and elastic properties (if using an elastomeric material), and the ability of the medium to decouple in the horizontal plane as well as the vertical plane. 
Manufacturers of things like spring supports, air bladders, and elastic support materials often give weight ranges to help customers select the right product but it would be very difficult to precisely account for all variables.  This may partially account for differences in the degree and types of improvement heard by listeners using decoupling devices.   Since most report hearing positive changes, it is probably a case of close enough being good enough.

@uberwaltz 

Now I do agree with Mahgister that they were likely not compressed enough.

That is an issue I have been working through by trial and error.  I am new to using springs under my gear/speakers and have been trying to achieve a combination of stability and appropriate compression and stiffness for the best sound, while maintaining as low a profile as possible.  The Nobsound devices are nice because they can be easily adjusted to change the stiffness but I am instead using individual larger springs.  I had a couple of instances where the springs were slightly over compressed (i.e., hardly any travel remaining) due to the weight of my speakers and I was able to solve the problem by placing an additional adjacent spring.  I previously asked this question in a different decoupling thread but did not receive any responses (I believe the same issue likely applies to speakers or turntables):

For those of you supporting heavy speakers on springs, do you recommend stiffer or more moderate spring support? In other words, how does the supported combined speaker/stand weight compare to the total available spring loading capacity....something moderate like 50% or something less (i.e., stiffer springs)?

 In addition to stiffness, I believe the issue may also include a component of compression/travel, which is related to the number of winds. 
Any experts here? 
Where is Geoff when you need him?

Amplifiers, speakers, and subs are on springs here now for a nice sonic improvement.  If you want an alternate to Nobsound, try simply purchasing loose springs.  By purchasing a few extra, I was able to add springs in strategic locations when needed to adjust the overall support.  For example, under each amp I have springs in the four corners plus one directly beneath the large transformer.  I also found you can place thin heat shrink around the springs and overlap on top and bottom to avoid scratching floors and the bottoms of your equipment....this is similar to what is shown on the Townshend site for their pods. 

The supplier linked below is fast, relatively inexpensive, and has a nice search tool you can use to enter your spring parameters. 
https://www.centuryspring.com/catalog/compression-regular?page=search&cid=compression-regular

@noromance

I used leftover Nobs springs directly to good effect.

Those Nobsound springs are quite small, aren’t they? If you play with the search tool on the Century Spring site, you can find larger diameter springs that may suit your needs, which should improve stability. The springs I used under my subs are 1.75 inches in diameter and the springs under my main speakers are 1.625 inches in diameter. I am looking at their S-3031 springs for my general electronics, which range from about 20 to 30 pounds each in total weight. OD of those springs is almost 1.3 inches so they should be quite stable. The free length is 1.0 inches and compression rate is 20#/inch so compressed at 5 pounds they would be 3/4 inch long in service. They are good for a maximum of 12 pounds each. This seems to offer a good, wide range size for my electronics, which are also somewhat mass loaded so total weight per spring will probably range from about 6 to 8 pounds. Unit price of the stainless steel S-3031 is $5.63 each so in the audiophile world that is a relatively benign $22-$28 per component. In comparison, Herbie’s Tenderfeet are $14 each.  If you order, make sure you get closed/ground ends.

@millercarbon , I started my spring journey a couple of weeks ago and now have most of my system on various springs.  I have experimented with different sizes and stiffness of individual springs instead of going the Nobsound route.  Although, it didn't always turn out as I envisioned with regards to which springs worked best with which components and speakers, I now have two heavy monoblocks, two heavy subs, and my two heavy main speakers all on appropriately sized springs, as well as most of my front end electronic components (but I need another set of low load springs to finish with my entire system).  I hear the sonic changes/improvements that you described in your post below, which is why I am curious about the comment by @mijostyn .

@lewm 

as is so often the case in this hobby, we have a phenomenon on one hand and a hypothesis on the other, and we marry them often without much evidence.

Shocker!  😎