Springs under turntable

MC, You wrote, "Audio is full of complex concepts and this is a big one: human beings DO NOT hear all frequencies the same."  Yes, that's right; it's called the "Fletcher-Munson Curve", and you didn't invent it.  It's why once upon a time a conventional receiver or integrated amplifier had a "Loudness" contour knob on its front panel.

Then you wrote, "So if there's no location information, and moving the subs around by feet all over the room never alters any bass detail, how can it possibly affect (nonexistent) bass detail if a spring lets a sub move a millimeter? Rhetorical question. It can't."
Here you are conflating location information with distortion.  If the sub moves in response to a low frequency audio signal, that means that some of the energy in the signal was lost in doing the work necessary to move the speaker.  This could cause an aberrant presentation of the musical signal at certain frequencies, due to loss of energy at certain frequencies.  That phenomenon is a form of distortion. So, in my opinion, it is best to anchor a subwoofer as firmly as possible in the listening environment.  You can argue the other side of that question, but not using the rationale presented in your last post.  You'll have to do better.  I don't disagree with your bit about bass location.  But I will turn your conclusion around; if the springs do nothing to affect bass detail or a sense of bass location, then why use springs at all?

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

https//youtu.be/dW9-r83IvhI

Your tympanic membrane moves immediately in conjunction with the pressure front created by whatever frequency of sound you care to talk about including bass. This movement occurs immediately and does not wait for a full wavelength to pass. But, it does take a period of time before the sound is registered and interpreted by the cerebral cortex. This probably occurs at the same time for all frequencies. Now, in deep bass it becomes not only hearing but feeling that are involve in assessing the sound. At some point it becomes only feeling if the volume is loud enough to register at all. 
The job of the enclosure is to isolate the woofer's rear from it's front waveforms so they do not cancel and to hold the woofer rigidly in space. Any movement of the woofer distorts the waveform. If the enclosure is sufficiently heavy and stiff it does not matter what it rests on. Unfortunately, that is a very difficult goal to reach so it is always best to anchor the subwoofer to a large immovable object like your house. 
The way I use my subwoofers is significantly different than say millercarbon. I cross over to them much higher at 125 Hz. This is up into the range that can be located. So my subs have to be arranged around the satellites in a symmetrical pattern to maintain a proper image. 
I also have to duplicate the radiation pattern of a line source so that the subs can keep up with the satellites as distance away from the speakers increases. It is certainly true that a bass instrument's higher frequencies and harmonics locate the instrument. The fundamental does not even have to be there. What goes AWOL is the sensation. I can make an EQ preset that chops everything under 40 Hz. Switching back and forth between the normal curve and the 40 Hz chop will not change what you here so much but all the sensation you get being at a live concert will disappear, gone. Those frequencies under 40 Hz are what makes music breath. Unfortunately, it is so easy to corrupt that end of the spectrum with room problems, phase inconsistencies, poor enclosure design and execution, and under powered amplifiers.  But, when you get it right it is a beautiful thing.

Mijostyn's sub array worked for me (I don't have nearly the quality of subs that mijostyn has) primarily because of my room set up did not accomodate sub placements throughout the room. (Thanks mijostyn). I also cross pretty high based on the simple premise that I wanted a speaker (sub) to "take" the "whole" instrument. A tweak that might work for those using an array is sending left channel signals to the left side subs of the array and right to the right. On many recordings, it's clear, by hearing and feel, that that double bass is clearly on the left of center. YMMV.

@mitch2  thanks for posting Townshend link, I use them with Cube speakers and imo they improve clarity.

I came across this which may be of interest as well

https://youtu.be/5ihzvD3urc4

@Derek, that is the right way to set them up as dedicated right and left channels. What crossover point are you using ? You do no want to go too high. Some harmonics coming from bass instruments are up in the mid range. Certain sounds like strings tapping the fretboard may be up in the treble. Bass instruments are usually mix towards the center so both channels are operative. You can go mono with high crossover points because you will start messing with the image to some degree. Mono is not a problem with crossover points below 80 Hz as we all know that localization is difficult below 80 Hz. The sub also do not need to be arranged symmetrically around the satellites although to me asymmetry is visually disturbing. (there's that silly brain again). 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. Putting subwoofers under LS3 5A's is quite the experience. With your eyes closed you would swear it was a much larger system. You open your eyes and see those little things and you start looking for the other speakers. 

@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.  

I just fixed my brother in law’s turntable with the same issue, but the rubber on his had disintegrated. I found these https://www.mnpctech.com/collections/turntable-lsolation-feet and installed them without any issues.

@mitch2 , you are exactly correct. Low bass pushes the suspension into it's nonlinear zone. Then there is doppler distortion on top. 
If you have at least two subwoofers of high quality you can push the high pass filter up as high as 150 Hz. Imagine doing that to K horns. JEEZ!

I chose the easy way out for my full size, 185 lb. speakers using spikes.  I have a custom listening room with 12" thick, steel rebar reinforced, 3000 lb psi poured slab.  At least no vibrations are going from the floor up, possibly only the speaker itself vibrates.  I like Townsend platforms and springs, possibly for my next speaker.

I use the Townsend Seismic Sink (bladder) for two decades under a VPI TNT VI+ turntable.  Without it, I would have junked the table as it has poor vibration control with those fancy feet.  

For the rest of my equipment, I use various versions of Stillpoints (ultra-minis, SS) and they work great after testing out a dozen others (some were equally good, most worse, none better).  I also use a buckwheat pillow under an EAR 324 phono preamp and CD recording/editing machine (better than anything else, inelegant and very inexpensive).  The buckwheat pillow is rather good overall; however, I wouldn't use it near my tube equipment (heat).  

@fleschler ,

Did you get the buckwheat pillow idea from Tom Port?

My comment from a few weeks back:

My turntable and monoblocs are on springs. When I added them to the phono-preamp, I lost bass response. Frequency response tilted up in the mids. No resonant drone or rumble. Replaced with metal cones and all returned to normal.

I revisited this. I was using leftover loose springs for the above. I’ve since received another set of Nobsound springs; this time with no pads stuck on. Test 4 footers under the phono amp. 1 spring per footer. Added brass weights to counter the heavy transformers on one side.. Awesome! Cones gone. Danny Thompson bass is in the room.

Anyone else using Nobsound springs under their turntables, amps and speakers?

Yes. I use them under my turntable, amps, and preamp. I had used metal spikes under my amps and switched to the Nobsound springs. I wasn’t expecting much. I even thought they might not work. They did improve the sound stage. I guess there were some microphonics I wasn’t aware of before the springs. I placed them under my turntable and there seemed to be some slight improvement. I didn’t notice any changes with my preamp. I’ve left them all in place. No reason to remove them.  

Suggest combining your springs with 3 cups and balls arranged in a equilateral triangle for even better seismic isolation.

After trying a tremendous number of things I had settled on BDR and was using Shelf, Round Things and Cones under everything. This went on for a good 30 years. Until around 2 years ago when I was persuaded to try spring isolation. 

Ordinary springs worked so much better and cost so much less it was hard to believe. Plain springs are cheapest and would be the way to go, except for how hard it is to find them in the right size dimensions and weight ratings for each component.

So I decided to try Nobsound, and quickly found they are equivalent to a single spring only with the added advantage of adjustability. 

Because of all these various factors, at one point my whole system was on springs, with Moabs and some of the subs on individual springs, and the rest of the subs and all other components - amp, phono stage, turntable - on Nobsound.

With Nobsound it is absolutely crucial to adjust the number of springs per footer by listening. If this is not done it is very easy to think they make the sound bloated (too few springs) or thin (too many) and I have seen people return them disappointed due to not doing this. 

That said, all the Nobsound and other springs have been sold or given away to friends as I have upgraded to Townshend Pods, as they are on a completely higher level. There are still a few plain springs- under the granite under my amp, the step down transformer, and conditioner. Not much else will work in these odd locations. 

The reason for trying Pods is an interesting story. With everything isolated and a DBA with incredible deep bass I began noticing intermittent problems with a very low rumble. I was at first thinking my turntable bearing was going bad after 20+ years. It even showed some marks, that might have been it. But polishing and refinishing, nada. Same problem.

Gradually dawned on me isolating the system on springs might have resulted in a resonance at this frequency. Testing showed sure enough, replace one Nobsound spring with a Cone, no more rumble. So it was resonance after all.

Pods are damped. John Hannant assured me no one had ever had anything like this with Pods. I gave them a shot, and not only eliminated the rumble but got a major across the board sonic improvement. One thing led to another and so today no more Nobsound. But they are totally the best thing for the money I have ever tried. 

On damping and cost - If you are using Nobsound springs and you flick the individual springs with your fingernail and they ring, wrap one turn of PTFE tape around the full circle. Tight enough to damp but loose enough not to deform. It may not be as good as Townshend (which I've not tested) but it will be $000 less expensive.