Springs Under My Speakers: What's Happening?

[MAB]

Later in the video they measured the sound from the loudspeakers using a microphone. So if there were changes, there were changes in the sound.

Thanks for pointing this out I stopped watching the video when I noticed the accelerometer was placed in different locations on the speaker from trial to trial. I just watched the end with the in-room measurements. there were actually no changes in the Frequency response:

They do provide the data, it shows no change.:

On the order of run to run variability, which I am careful to show in the tests I post here. Or maybe the difference is due to the isolation materials, in which case it is verifiably tiny. So no change in the FR.

I guess I am not surprised they then rolled out the time-domain argument, evoking PRaT along the way. The time domain graphs hey show are incredibly weak, and if the time-domain differences are significant then would show up in the FR. And now that you pointed out the end of the video, I now realize they are either naïve, disingenuous, or complete carnival barkers.

So if there were changes, there were changes in the sound.
And that’s the claim I was addressing - that there was “ no mechanism by which the sound could change.”

Yes there are changes in the vibration spectra of the cabinet, they weren't able to measure sound changes. Once again, they are some effects, but not large enough to change the frequency response. And the measurements actually support.

The level of audibility is another issue, and presumably would be variable depending on the loudspeakers/floor/what might be sitting between them, etc.

I do share your skepticism when it comes to manufacturers not using actual music or sound signals to demonstrate the claims.
For instance, there’s a nice Townshend demonstration video using vibrometers showing how loudspeakers placed on their platform are isolated from impact vibrations on the ground around the loudspeaker. And there’s also a demonstration showing that the loudspeaker on the floor when it is tapped shows ringing, whereas when they are sitting on the platform when they are tapped, they show a much cleaner impulse response without the ringing.

So something is going on there.

However, what I want to see are such results demonstrated using musical signals, or at the very least a Sonic impulse signal sent through the drivers, showing the same phenomenon, rather than just impacts upon the speaker.

They disproved their own product's effectiveness in this video. They should publish a whitepaper with the data, probably include the FR first so we can start with the important things.

 

[dfuller]

Thanks for pointing this out I stopped watching the video when I noticed the accelerometer was placed in different locations on the speaker from trial to trial. I just watched the end with the in-room measurements. there were actually no changes in the Frequency response:
View attachment 462740

They do provide the data, it shows no change.:

View attachment 462743
On the order of run to run variability, which I am careful to show in the tests I post here. Or maybe the difference is due to the isolation materials, in which case it is verifiably tiny. So no change in the FR.

I guess I am not surprised they then rolled out the time-domain argument, evoking PRaT along the way. The time domain graphs hey show are incredibly weak, and if the time-domain differences are significant then would show up in the FR. And now that you pointed out the end of the video, I now realize they are either naïve, disingenuous, or complete carnival barkers.


Yes there are changes in the vibration spectra of the cabinet, they weren't able to measure sound changes. Once again, they are some effects, but not large enough to change the frequency response. And the measurements actually support.


They disproved their own product's effectiveness in this video. They should publish a whitepaper with the data, probably include the FR first so we can start with the important things.

The frequency response measurement there is limited to 300hz, so any meaningful changes where isolation from the structure might actually do something aren't even in the measurement.

I'm not entirely sure what they were aiming for here.

 

[audiofooled]

You can't measure this with microphones and see "changes in the frequency response", certainly not with usual test signals, nor SPL levels that are considered normal for casual listening. Which also means you can't detect it with your ears either under these circumstances.

However, I'm sorry to say that effects are profound and detectable (not audible per se), but detectable by other mechanisms in our body. In circumstances you've dealt with most of the audible room problems, including time domain problems and you want to listen at least comfortably loud, that's where the problems may arise.

One has to remember that we are putting audio frequencies and investing quite a lot of energy at peaks of the impulsive signals, that reaches the floor, a hard surface of a different acoustic impedance, at which point waves are transmitted at speeds much more faster than through the air and reach all other solid surfaces, quite possibly before sound ever reaches your ears.

For relatively broadband transient signals (quick bass drops) reproduced by time aligned systems, through this kind of transmission trough solid surfaces, chances are high that you are hitting just about every non audio related object's resonant frequency and it will want to sing along with it. There's also feedback from the floor into the loudspeaker cabinets. This is not related to normal cabinet resonances (you may have none that are audible), but mechanically induced vibration. It's the energy that's refracted inside the floor and bounced back at frequency that was "injected" before, now that the system is already tracking a different frequency in the signal. For big and very clean systems this may degrade perceived clarity.

Having experimented with this, I must say that decoupling may be worth the investment, but improvements may be marginal and not always for the better. It will depend on Q of resonances and has to be addressed accordingly. If you're lucky in finding a right solution, what you may perceive is that the room can now take more pressure, not being that easily "overloaded", you've restored clarity that your system already had in the first place. Finally, if you occasionally crank it up, it stays clear, with no audible changes in tonality.

I hope people understand that we shouldn't talk about changes in frequency response or perceived tonality. On the contrary, nothing should change in magnitude response, and stay that way, with increase in SPL.

Anecdotally, the most improvement you may perceive is in clarity of bass signals with poor correlation, which are usually lower in level than mono part of the signal, that is if perception of Auditory Envelopment is that you're after. If you actually want perception of acoustic space that is larger than you listening room's dimensions, small objects that are resonating all around you will remind you of your room boundaries.

In industry this is effectively measured with velocity probes. Time will tell if It may be beneficial for audio, at least I hope so.

You all have a nice day.

 

[Thomas_A]

Regarding IMD, have anyone on ASR measured the IMD of a 40-100 Hz/5 kHz a two-way speaker with traditional woofer/tweeter using hard vs soft feet?

 

[MattHooper]

Thanks for the analysis. Again, I agree with being critical in regards to a video that is produced by a company selling a product.

Still…I was addressing the claim that there was no mechanism by which to alter the sound from the loudspeaker in terms of such isolation products (and more specifically that there was no mechanism available in the scenario that I tried).

Yes there are changes in the vibration spectra of the cabinet, they weren't able to measure sound changes.

That doesn’t makes sense to me.

Sound is vibration.

Since a microphone recorded the sound output any measured reduction in ringing or resonances indicates a change in the acoustic energy reaching the microphone.

Meaning the changes in resonances and ringing are part of the acoustic signal reaching the listener.

If what you are ultimately arguing is that they did not demonstrate effects that are likely audible, that’s another thing and that’s a question I left open which I wasn’t referencing that video to address.

But on that subject: Is it your position that time domain effects like ringing cannot be audible unless they show up specifically in the frequency response?

Another aspect is what I brought up before, mentioned by PSB speaker, designer Paul Barton, that a speaker coupled to a wood floor that effectively amplifies those vibrations might be felt by the listener of the listening position, so that the listener is effectively getting to stimulus from the sound - the sound waves coming through the air combining with the vibrations that arrive a bit earlier, and this he says can have an effect on the perception of the sound.

That seems to fit well with my experience, because as I’ve said, with louder music I can literally feel the floor, vibrating around the base of my speaker when I stand near it, as well as feel some of the vibrations in my seat and the ottoman that my chair is on.
But when I put the Spring footers on the vibrations near the base of the speaker were gone, and I also no longer felt near as much vibration coming through my legs, and perhaps this would explain why I say I lost some “ feeling/sense of visceral connection or impact” that made the sound seem more solid when the springs were removed. (this lack of vibration coming through the floor once the springs are under a speaker has been remarked up upon by other people using decoupling as well).

Found a quote from Toole’s work:
Toole Quote, from Sound Reproduction: The Acoustics and Psychoacoustics of Loudspeakers and Rooms, 3rd Edition, 2017, Chapter 9, p. 190:

“At low frequencies, the boundaries of rooms—walls, floor, and ceiling—can be set into vibration by the sound field, and these surfaces can themselves become radiators of sound. In lightweight constructions, such as wood-frame walls or floors, this effect can be significant, adding to the complexity of the sound field.”

Looks like he’s talking about the sound emitted from the speakers drivers, though if speaker vibrations coupling to a floor that can be felt, perhaps that is relevant as well.

As I’ve said from the beginning of this thread, I’ve been using my experience more to throw out questions to see what ASR members here think or have to contribute.

And there’s been range of replies from knowledgable members, some of which are doubtful of any effect, and others of which argue for an effect. So it’s been interesting to observe.

 

[MAB]

The frequency response measurement there is limited to 300hz, so any meaningful changes where isolation from the structure might actually do something aren't even in the measurement.

I'm not entirely sure what they were aiming for here.

I hard to know. The video is missing so many critical pieces of info that would actually clarify if there are audible sonic differences, let alone the large and obvious changes that are often reported. Despite the omission of critical data that would trivially support their point, let me take their statements of fact at face-value.

They make a claim by comparison:
"The movement of the cone can be as little as 1 micron. Ringing by the speaker itself, or from vibration coming from the other speaker can be more than that 1 micron."

1um of driver travel is around 25dB for a typical driver, give or take. This is below the noise floor of a quiet room. The effect they claim to be improving should be worth much more than 1um of cone motion if it is to be audible.

 

[MAB]

Thanks for the analysis. Again, I agree with being critical in regards to a video that is produced by a company selling a product.

Still…I was addressing the claim that there was no mechanism by which to alter the sound from the loudspeaker in terms of such isolation products (and more specifically that there was no mechanism available in the scenario that I tried).

I am addressing if any of this is audible.

That doesn’t makes sense to me.

Sound is vibration.

Since a microphone recorded the sound output any measured reduction in ringing or resonances indicates a change in the acoustic energy reaching the microphone.

I am sure they measured changes in cabinet resonances and vibrations. I am also sure the actual vibrations cause a sound in the room, perhaps around 25dB by the accounting in the video. Yes, you can rest easy that there are physical mechanisms where vibrational energy is coupled between speakers. The effect is just not detectable without measuring equipment much more sensitive than an ear.

Meaning the changes in resonances and ringing are part of the acoustic signal reaching the listener.

Yes they are. By their own calculation, perhaps 25dB at most. And this 25dB of resonance would be while the speakers are playing at high volume. So yes there are resonances, it's just below detectability.

If what you are ultimately arguing is that they did not demonstrate effects that are likely audible, that’s another thing and that’s a question I left open which I wasn’t referencing that video to address.

I had no idea you were trying to answer such a narrow question. It's fine, it doesn't change my answer.

But on that subject: Is it your position that time domain effects like ringing cannot be audible unless they show up specifically in the frequency response?

Ringing is not necessarily a time domain thing, but I think I know what you mean. It's not really about me and my position on time-domain distortions. Fourier already did this work, and in all but the most contrived and unrealistic scenarios also result in large FR variations. Toole and many others studied and published on the audibility of these time domain effects. Time domain differences or distortions need to be large to be audible, and also need to be listened to in a reflection-free environment.

Post in thread 'Time Domain measurements?'

Apr 29, 2020

1. Is time domain something that could be added to the measurements in the reviews here? Or explain why it's not important?

It could be but it is not important. That is why it is not in CEA-2034 standard we follow.

Research shows that we can sort of hear timing information in anechoic chamber and with headphones. In a real room though, it simply is not audible because reflections in the room all come at vastly different timing and mix together. What the speaker does at the start simply doesn't matter.

See the paper, On the Audibility of Midrange Phase Distortion in Audio...

• amirm

• 

And to be clear, the phase distortions presented presented in this video are really tiny.

 

[Pareto Pragmatic]

I see the measurable/audible question has come up. My 100 year old floor has an obvious effect on the sound, and my feet. Big enough that I cross my Sierra LXs over with my 30hz floor! I think my floor can serve as a "worst case" scenario, where isolation might or might not have a measurable and audible effect.

Given the question, "how do I measure the effects of my floor?", the answer turns out to be not simple. In the bass, the floor shares dimensions with the room, so those effects can "hide" in room modes. Sweeps won't capture how energy concentrates in floor harmonic frequencies from the general energy in the floor. White noise, better, but lacks the effects of musical note "spikes". In any case, I can boil things down to 3 measures, but three very particular measures based on a LOT of measuring and moving things around over the years.

First, my floor spits out sound with a 200ms delay:

In fact, you can get an idea of the level of sound from this next one, if you look above 10kHz, that's my floor. Not late reflections (I've minimize those), not a sampling mismatch. That is my floor winding down, slowing down, specifically the floor boards. A new rug pad got rid of the 200-400ms stuff... for a few days until loose floorboards in the back 1/3 of my room beat the rubber backing into submission. It's better than it used to be, even for all that punishment.

Looks pretty phasey up there, doesn't it? Everywhere, really. So there's a pretty big effect, particularly if we pile that on top of a room mode at a given frequency.

So, 30hz is my main floor, 50hz is the floating floor in the front 2/3 of the room. With the harmonics, those two behave in... interesting ways. Way above 200hz, in fact.

To test my assumption, which is that controlling the floor will help my phase issue, which should "calm" my floor movement overall a bit, I decided to do the following test. Admittedly after trying it a few times, but this time I added a control.

I had REW's EQ wizard give me a solution on white noise, then I shifted all the frequencies to be in phase with the floor (200ms delay). The results are below.

NOTE: This is a different type of sweep, done into RTA. The mic volume was 70db, but the peak of the sine wave is 40. So broad. It's an AV mains sweep, so should be slowing rolling off below 200, and then dropping off the table (into the noise floor) by 60. I use a down-up sweep, that bounces off 20hz pretty fast, "energizing" my floor. This is what I use to test my EQs for floor effects, along with a bass sweep of course, because room modes exist.

Green = REW solution. Red = phase shifted (generally 1-2hz shift). Note the better match to an AV target in the bass with the phase shift. And the huge amount of energy at 20hz in the REW solution.

Honestly, a bit more pull down of 30 and 50, that would be pretty good... but I need 2 PEQs on 2khz, really. Squeaky floor boards. Not the point here.


That's a long way to set this direct answer to isolation feet/pads. You can assume I've tried many things. In my case, barely any change (but good change) to worse with a variety of isolation products and schemes. I'm talking a 1 db shift at a couple frequencies. Taking 7lbs of weight out of my stands? WAY bigger improvement, way more measurable effects. So might they work for some?

I can see isolation devices working best if the issue is a floating floor system, particularly a click together system. I can see how that might create issues at higher frequencies where something like Sorbothane might help. But absent a damped spring system, I can't see anything handling vertical motion from a floor well. Waste of time and effort if that's the issue. There are better ways to get improvement, in my experience at least.

 

[audiofooled]

I see the measurable/audible question has come up. My 100 year old floor has an obvious effect on the sound, and my feet. Big enough that I cross my Sierra LXs over with my 30hz floor! I think my floor can serve as a "worst case" scenario, where isolation might or might not have a measurable and audible effect.

Given the question, "how do I measure the effects of my floor?", the answer turns out to be not simple. In the bass, the floor shares dimensions with the room, so those effects can "hide" in room modes. Sweeps won't capture how energy concentrates in floor harmonic frequencies from the general energy in the floor. White noise, better, but lacks the effects of musical note "spikes". In any case, I can boil things down to 3 measures, but three very particular measures based on a LOT of measuring and moving things around over the years.

First, my floor spits out sound with a 200ms delay:

View attachment 462768


In fact, you can get an idea of the level of sound from this next one, if you look above 10kHz, that's my floor. Not late reflections (I've minimize those), not a sampling mismatch. That is my floor winding down, slowing down, specifically the floor boards. A new rug pad got rid of the 200-400ms stuff... for a few days until loose floorboards in the back 1/3 of my room beat the rubber backing into submission. It's better than it used to be, even for all that punishment.



View attachment 462769

Looks pretty phasey up there, doesn't it? Everywhere, really. So there's a pretty big effect, particularly if we pile that on top of a room mode at a given frequency.

So, 30hz is my main floor, 50hz is the floating floor in the front 2/3 of the room. With the harmonics, those two behave in... interesting ways. Way above 200hz, in fact.

To test my assumption, which is that controlling the floor will help my phase issue, which should "calm" my floor movement overall a bit, I decided to do the following test. Admittedly after trying it a few times, but this time I added a control.

I had REW's EQ wizard give me a solution on white noise, then I shifted all the frequencies to be in phase with the floor (200ms delay). The results are below.

NOTE: This is a different type of sweep, done into RTA. The mic volume was 70db, but the peak of the sine wave is 40. So broad. It's an AV mains sweep, so should be slowing rolling off below 200, and then dropping off the table (into the noise floor) by 60. I use a down-up sweep, that bounces off 20hz pretty fast, "energizing" my floor. This is what I use to test my EQs for floor effects, along with a bass sweep of course, because room modes exist.

Green = REW solution. Red = phase shifted (generally 1-2hz shift). Note the better match to an AV target in the bass with the phase shift. And the huge amount of energy at 20hz in the REW solution.

View attachment 462770


Honestly, a bit more pull down of 30 and 50, that would be pretty good... but I need 2 PEQs on 2khz, really. Squeaky floor boards. Not the point here.


That's a long way to set this direct answer to isolation feet/pads. You can assume I've tried many things. In my case, barely any change (but good change) to worse with a variety of isolation products and schemes. I'm talking a 1 db shift at a couple frequencies. Taking 7lbs of weight out of my stands? WAY bigger improvement, way more measurable effects. So might they work for some?

I can see isolation devices working best if the issue is a floating floor system, particularly a click together system. I can see how that might create issues at higher frequencies where something like Sorbothane might help. But absent a damped spring system, I can't see anything handling vertical motion from a floor well. Waste of time and effort if that's the issue. There are better ways to get improvement, in my experience at least.

I suppose this could do wonders in your room :

~29Hz fundamental and how the room responds:

Minimum phase phenomena down to DC:

Hit the right frequency with sufficient amplitude and you could be homeless...

 

[Sal1950]

My JBL HDI-3600s came with soft rubber sorbothane type feet, that's the way they stayed.
I don't understand why manufacturers mostly insist on 4 feet when 3 would provide a more stable platform? True for not only speakers but electronics too.
I did read in Stereophile that the latest Magico S5 2024 uses a 3 point outrigger base, maybe a prior thing for them, I don't know.

 

[thewas]

I don't understand why manufacturers mostly insist on 4 feet when 3 would provide a more stable platform?

I think it has to do with the norms of tipping over point (for child safety) which have become stricter in the last years, so you see also more often floorstanders with extended feet then in the past.

 

[Sal1950]

I think it has to do with the norms of tipping over point (for child safety) which have become stricter in the last years, so you see also more often floorstanders with extended feet then in the past.

Keep the crumb grabbers out of the Hi Fi room.,
JK

 

[PGansz]

If you were to design floor standing outriggers, wouldn't you want more of them and not less? Less means less surface area, impacting the amplitude of the signals to the floor.

Frankly, the ultimate system would be spreading the entire "load" through a lattice system against the floor/ground.

The point being, is that most cabinets ring or don't absorb all the energy very well, so one way to dispense of it is to transmit it out, through a device which would minimally impact the actual floor transmission.

Hence, more and larger outrigger feet, not fewer and/or smaller.

 

[Heinrich]

If you were to design floor standing outriggers, ...

You mean like a cruiser jet has multiple wheels instead of just three? You're mentioning signals and ringing energy to be dispensed, what exactly are you after? Maybe the mental map of the problem is a bit spotty with wide white areas in between.

Can we accept that there is no problem, actually, that cannot be solved with household materials and just one simple, yet effective rule of thumb?

 

[izeek]

Yes, exactly what I'm looking for. Honest opinions from people who are willing to experiment with well-known decoupling suspension devices that have been working in the automotive, DOT, aviation, construction of high-rise/bridges, and the HD equipment market for 100+ years.

The science is very well known, apart from the HiFi world, for some reason.

Measurements give people like me, data if I need it to fix a problem, not fix a solution. Vibration control adds longevity to any product it's attached to, no matter what it is. Vibration and heat are the number one killers of anything electronic, along with dust, soil, or moisture.

Decoupling any speaker system, especially sub/bass removes the huge passive driver called the floor that arrives at your bottom/feet before it arrives at your ears. It will always add clarity in the sub/bass frequencies and, in doing so, add clarity to all other frequencies.

Vibration control in all combustion engines is the main reason they stay together and last as long as they do (now). Currently, it's not uncommon the see 10,000 hours or 1.5 million miles on a diesel engine or 350,000 miles on a gas or LPG engine behind designed front and rear crankshaft damping/vibration control. Better lubricants, and cleaner burns in the combustion chamber, resulting in practically ZERO wash from over-fueling and near ZERO wear as a result. If not for the air (that always has some contamination) in combustion engines, engines would likely live longer than most humans under normal, everyday use.

The facts are simple: most of the HiFi world is still in the stone age. Another fact is top-notch engineers don't work for speaker companies or people who design and build HiFi gear. They are building sound walls, bridges, high-rises, freeway overpasses or crap for NASA, not Marantz or Wilson.

This is for fun, keep that in mind, most current manufacturers of HiFi gear sure do.

My best Regards

Decoupling any speaker system, especially sub/bass removes the huge passive driver called the floor that arrives at your bottom/feet before it arrives at your ears. It will always add clarity in the sub/bass frequencies and, in doing so, add clarity to all other frequencies.

i needed to see that. it's what i think and have experienced. just done differently from springs. i used mass, concrete pavers, on my suspended wood floor.
seems to have done a great job.

 

[izeek]

That’s what I was thinking of doing at one point. It’s really cool to see somebody who actually did it.



Yeah, it can be a game of just sort of pushing resonances around and seeing what happens.

I quite enjoyed having fun with the process.

(there’s a good review of new Magico speakers in the latest issue of Stereophile, where John Atkinson discusses material resonances with the Alon Wolfe. And they discussed how it’s a misunderstanding somehow have that materials like stone or aluminum don’t vibrate audibly, when they do ring quite a bit, and so if you want to make a heroically designed enclosure, and you are using something like aluminum, you also have to incorporate damping. Otherwise you’re just moving around resonances. That’s basically the approach I took. I noticed that even two thick sheets of granite still rang when I knuckle rapped them, and then I used car sound taping material between them, and that really deadened the sound. However I assume they still resonate, so they still may be contributing something to the sound of the set up, and how they interact with my speakers and or the floor.

Yeah, it can be a game of just sort of pushing resonances around and seeing what happens.
i agree. ive found everything i used in my decoupling journey, had it's own effect.
mdf>wood>particle board, etc. different rubber compounds. for the record, sorbothane sucked in my system. dulled the presentation

 

[PGansz]

You mean like a cruiser jet has multiple wheels instead of just three? You're mentioning signals and ringing energy to be dispensed, what exactly are you after? Maybe the mental map of the problem is a bit spotty with wide white areas in between.

Can we accept that there is no problem, actually, that cannot be solved with household materials and just one simple, yet effective rule of thumb?

I didn't say it can't be solved with household materials, I am refuting the idea that three or four outrigger spikes do anything positive but keep the speaker upright.

I use dense padding between the speaker and stand, and between the stand and floor for the reasons I describe.

 

[Thomas_A]

I didn't say it can't be solved with household materials, I am refuting the idea that three or four outrigger spikes do anything positive but keep the speaker upright.

I use dense padding between the speaker and stand, and between the stand and floor for the reasons I describe.

Whatever you use as outriggers, the point of having soft feet is to put the fundamental resonance frequency below the speakers frequency range. It may sometimes be a bit unstable when having kids around since such a speaker will sway slowly back and forth when given a gentle push. For the speaker to not resonate somewhere in the bass frequenciies, three, four, five points does not really matter as long as the criteria is fulfilled.

 

[Heinrich]

I didn't say it can't be solved with household materials, I am refuting the idea that three or four outrigger spikes do anything positive but keep the speaker upright.

I use dense padding between the speaker and stand, and between the stand and floor for the reasons I describe.

As said before, for a human the topic is a triviality. When I asked an AI to solve the 'problem' just ninsense came out. As the AI replicates 'common wisdom', as to say, I was wondering what the ideas are, and where they come from.

First of all it seems, that giving a speaker a stand is something that cannot be avoided - same as with cables. It is a quite responsible task to be accomplished. The stand connects speakers to the house like the cables connect them to the amp. The consumer is left alone in doubt if one or the other solution is ideal. Ideal, not just good enough. Ideal may involve quantum cleansing of electrons with super conductive cable lifters by non-local entanglement. TlDr: Causality and realsim get dropped.

On spikes: connect the speaker to the floor (as if they were screwed on), adding the floor's rigidity (if there is) to the set-up, will rattle in all practical implementations

On floating, soft stands: allows for the speaker box to move according to the cone's weight in relation to the box's weight, typically by a factor of 1/1000 ~ -60dB, and it is perfectly linear

What would you say? You use doubled up floating, is that needed? For sure not. I've seen way worse, though. I see it like this: the consumer is invited to hand over more expenses to the dealer. Or to stay in unrest, actually not enjoying his already expensive purchases. Threads like this do not settle the case, despite that being as easy as it gets - with a tiny bit of under-graduate science under the sleeve.

 

[Peterinvan]

My understanding is that the speaker box needs to be rigid and as anchored to the ground as possible to prevent distortion. I cannot see how springs would not make it worse.

My stands are filled with dense sand and spiked to the floor.