Vibration Management
- Thread starter PeterA
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I understood what you wrote and I really did appreciate your intent. My point was that just that as with most things, there's most always more than meets the eye and high-end audio is certainly no exception.
That you gave up being interested in my product ages ago is itself interesting because I had no product to pitch to you. Nor have I tried to pitch a product to anybody for perhaps 7 or 8 years. But the concepts, theories, methodologies, and performance potentials I do try to pitch.
I appreciate your listening to the videos and hopefully you listened at least with a cheap set of earbuds. I don't think one can find much fault with these humble in-room recordings (which like I presume with others' recordings pale in comparison to in-room listening) using my iPhone and a Shure MV88 microphone.
To the best of my knowledge I've only been pitching alternative concepts and methods all of which hopefully have everything to do with performance potentials. Now it just so happens that I already have a working design that IMO, substantiates my concepts, methods, and performance claims. Perhaps that's where some think I'm pitching product.
No disrespect taken, Marc, and I appreciate your constructive criticism. Yes, I'm well aware how any of this may come across. In fact, that's why I stayed away from this forum for almost 2 years and to this day I deliberately avoid the vibration mgmt threads, as tempting as it is to jump in head first into some of them. However, with this thread I still routinely receive email notifications and from time to time I read them and in this case, since Peter opened this thread about my claims several years ago, I reluctantly posted to it a few days ago.
But at the same time, or the other side of the coin is that I think it serves all of us well to be reminded that traditional concepts, status quos, historic ways of doing things, etc or just because everybody's doing something a certain way doesn't necessarily make it right nor best. Old science is routinely disproven by new science, same with philosophers and their philosophies, and yes for high-end audio too. Very little is written in stone and that should imply that everything else needs to be routinely re-evaluated and that we should be open-minded to new concepts and methods. Especially in performance-oriented industries where performance is absolutely paramount to all other things.
IOW, I've been the recipient of plenty bloody noses for daring to share something different from the status quo and so sometimes I'm perhaps a bit more on guard than I should be.
Anyway, thanks for the note.
I’m curious: did Taiko Audio or anyone ever produce a product with Stehno’s technology?
I have been working on vibration management of my stereo system these past four years. First, I'll start by summing up. Springs isolate, rubber dampens. Rubber can isolate too, but only in a limited frequency range based on shape, loading and durometer. Rubber isolators/dampers must be used carefully because they can and will color the sound due to their nonlinear properties. Wood footers also offer isolation/damping but will also color the sound.
Let's start with springs. Decoupling speakers, amps or other front end components from the floor and shelves with springs is an effective start to isolating audio gear from the structure borne vibrations. A spring/mass system has the physical characteristic of responding around its natural frequency but has little response to frequencies outside the fn. A tonearm and phono cartridge, for example should ideally have a natural frequency between 8-10 Hz. It needs to be above the frequency of a warped record so as not to be excited by the rise and fall of the vinyl but not too close to the minimum music notes of 20 Hz. A tonearm/phono cartridge system natural frequency can be calculated knowing cartridge compliance and the effective mass of the tonearm. (The spring is in the phono cartridge.) If the fn of the tonearm/cartridge is too low or too high then it becomes difficult for the tonearm to track the record effectively. Worst case the tonearm will skate right off the record.
Placing springs under speakers, amps or sources is also effective at isolating these components from vibrations. The trick is achieving the ideal natural frequency, fn of 3 Hz and also keeping the components stable. We do not need our speakers, amps or DAC rocking to and fro to the music. I found the most effective way to isolate components is to add springs to a sub shelf and then allow the component to rest on that isolated sub shelf while using either the manufacturer's feet on the component or our own selection of feet/dampers between the component and the sub shelf. I placed four 48 lbf/in springs on each of my amp stands (see picture below) isolating the amp stands from the floor. Based on the weight of my amps, I achieved a fn of about 6 Hz. I'm using compression springs. I have concluded that the best way to achieve a fn of 3 Hz will be to use extension springs but then the sub shelves will need to be suspended from some sort of superstructure. I haven't gone that far yet. Even at a fn of 6 Hz, my amps are very well isolated.
What I found when I isolated my amps- and step by step my front end components using springs is better, more focused imaging. I hear much more detail and clarity. So much more detail that at first it distracted me from the music. It took some getting used to. As I have seen some do, alternate footers can be used with the components resting on the isolated sub shelf to taylor the sound to their tastes. In my case, I have chosen to stay with the manufacturer's footers on my components.
Active isolation shelves are an improvement over a spring/damper suspension system. Just look at today's automobiles. Higher end cars are using active suspension systems for improved handling and ride. Otherwise cars use springs for isolation and shock absorbers for dampers. A car's suspension system fn is about 3 Hz as well. Hit a wavy road at just the right speed and it can lead to an exciting ride (and also dangerous) as the car is excited near its fn. The car will start moving up and down at a high amplitude.
The first photo shows my amp stands modified with coil springs over the original spikes. The right diameter made the springs a perfect fit for these amp stands. The second photo shows an accelerometer plot when all is quiet. The third photo, which while it cannot be seen I am tapping the floor next to the amp stand with a steel ball while the accelerometer is sitting on top of the amplifier. Almost no response at the amp cover. The third photo shows a response when I tap on the sub shelf that the amp is resting on. That shows the spring/mass system response at about 6 Hz- the fn. Other vibrations get through as well when I tap on the shelf that the amp is resting on. When I play music no floor borne vibrations reach the amps or my front end components.
Let's start with springs. Decoupling speakers, amps or other front end components from the floor and shelves with springs is an effective start to isolating audio gear from the structure borne vibrations. A spring/mass system has the physical characteristic of responding around its natural frequency but has little response to frequencies outside the fn. A tonearm and phono cartridge, for example should ideally have a natural frequency between 8-10 Hz. It needs to be above the frequency of a warped record so as not to be excited by the rise and fall of the vinyl but not too close to the minimum music notes of 20 Hz. A tonearm/phono cartridge system natural frequency can be calculated knowing cartridge compliance and the effective mass of the tonearm. (The spring is in the phono cartridge.) If the fn of the tonearm/cartridge is too low or too high then it becomes difficult for the tonearm to track the record effectively. Worst case the tonearm will skate right off the record.
Placing springs under speakers, amps or sources is also effective at isolating these components from vibrations. The trick is achieving the ideal natural frequency, fn of 3 Hz and also keeping the components stable. We do not need our speakers, amps or DAC rocking to and fro to the music. I found the most effective way to isolate components is to add springs to a sub shelf and then allow the component to rest on that isolated sub shelf while using either the manufacturer's feet on the component or our own selection of feet/dampers between the component and the sub shelf. I placed four 48 lbf/in springs on each of my amp stands (see picture below) isolating the amp stands from the floor. Based on the weight of my amps, I achieved a fn of about 6 Hz. I'm using compression springs. I have concluded that the best way to achieve a fn of 3 Hz will be to use extension springs but then the sub shelves will need to be suspended from some sort of superstructure. I haven't gone that far yet. Even at a fn of 6 Hz, my amps are very well isolated.
What I found when I isolated my amps- and step by step my front end components using springs is better, more focused imaging. I hear much more detail and clarity. So much more detail that at first it distracted me from the music. It took some getting used to. As I have seen some do, alternate footers can be used with the components resting on the isolated sub shelf to taylor the sound to their tastes. In my case, I have chosen to stay with the manufacturer's footers on my components.
Active isolation shelves are an improvement over a spring/damper suspension system. Just look at today's automobiles. Higher end cars are using active suspension systems for improved handling and ride. Otherwise cars use springs for isolation and shock absorbers for dampers. A car's suspension system fn is about 3 Hz as well. Hit a wavy road at just the right speed and it can lead to an exciting ride (and also dangerous) as the car is excited near its fn. The car will start moving up and down at a high amplitude.
The first photo shows my amp stands modified with coil springs over the original spikes. The right diameter made the springs a perfect fit for these amp stands. The second photo shows an accelerometer plot when all is quiet. The third photo, which while it cannot be seen I am tapping the floor next to the amp stand with a steel ball while the accelerometer is sitting on top of the amplifier. Almost no response at the amp cover. The third photo shows a response when I tap on the sub shelf that the amp is resting on. That shows the spring/mass system response at about 6 Hz- the fn. Other vibrations get through as well when I tap on the shelf that the amp is resting on. When I play music no floor borne vibrations reach the amps or my front end components.
Fascinating reading! Thank you for taking the time. The science is great for a non-techie to read. I have long utilized isolation for every component but not nearly with your level of understanding.
In our case, each component over years has ended up in what I can best call an isolation sandwich…isolation footers underneath and damping plates on top but often with mass damping on top of the plate (but the mass damping which is just pure weight does not make contact directly with the surface of the component).
Even our speakers (main and sub) have footers and damping plates with weight on top.
Each using a combination of Stillpoints Ultra 6s (but never on their own… but in fact always in combination with a HRS nimbus coupler) which combines the Stillpoints clarity and resolution with the much more natural tonal character of the HRS elastomer and aluminum combination.
And then Artesania damping plates with 270kg of weight on top across the system.
In our case, each component over years has ended up in what I can best call an isolation sandwich…isolation footers underneath and damping plates on top but often with mass damping on top of the plate (but the mass damping which is just pure weight does not make contact directly with the surface of the component).
Even our speakers (main and sub) have footers and damping plates with weight on top.
Each using a combination of Stillpoints Ultra 6s (but never on their own… but in fact always in combination with a HRS nimbus coupler) which combines the Stillpoints clarity and resolution with the much more natural tonal character of the HRS elastomer and aluminum combination.
And then Artesania damping plates with 270kg of weight on top across the system.
I have a bunch of charts showing how well the components are isolated while tapping a steel ball on the floor but I think the two charts showing the response of the main shelf vs the top of the preamp on the spring isolated shelf with the music playing says it all. I was careful to keep the scales consistent to avoid confusion. This time I am discussing the isolation of my front end components. I start with spring based footers. These footers are adjustable for load because they can each hold from one to six springs. The front end components should not be placed directly on the spring footers. At least, I found the sound was not ideal in that configuration. Best is when each component rests on a sub shelf that is isolated from the main shelf. Reference the first two photos of my preamp and DAC. I also experimented with sub shelf material- butcherblock, bamboo and Delrin. The preamps sounded best on butcher block but I'm tempted to try bamboo again.
I'll do my summary first. The first step to better sound should be to isolate the electronic components from vibration. Vibration comes primarily from the speakers- unless you live in California or Hawaii where ground movements are more severe. But then most people are likely not trying to listen to music during severe ground movement. Who knows, some people might live in an area where traffic causes vibrations up through their floors.
I show in the following charts how the spring footers are effective at isolating the audio electronic components from external vibrations. These spring footers are mostly neutral when it comes to effects on the sound. Now once the components are placed on well isolated shelves, then the next step can be performed- tuning the footers that are on the audio components. I prefer to use the manufacturers footers but that is just me. Others may find various types of footers in various configurations tailor the sound more to their liking. It's an interesting hobby because it has seemingly infinite permutations. Now that I am retired and had time to apply myself to finding some solutions to basic audio problems I'm disappointed in myself that I didn't think of spring isolation decades ago. It was always staring me in the face. End result is clarity, sharper image focus and more detail- gobs of detail but without sibilance.
What I show in the following charts is how these spring footers isolate the audio components from vibration. A spring mass system has a specific resonance point called fn- natural frequency. The ideal resonance point for audio, auto, etc is typically around 3 Hz. Best I can achieve with these spring footers is about 6-7 Hz. Still very good at isolating components. I would not recommend them for Turntables because 6-7 Hz is too close to the Tonearm/Phono cartridge resonance point. In the case of turntables, the isolators need to be 3 Hz. The only way to practically get there is with extension springs. Consider that to drop the resonance point from 6 Hz to 3 Hz requires the spring rate to be reduced by a factor of 4. That is not easy to do with compression springs and still keep the platform stable. But of course the other way to isolate components is with active isolation platforms- a more costly solution but even better isolation performance.
My accelerometer and FFT plots are limited to 50 Hz. That still shows the bass notes in the music finding their way to my component shelf. In fact, the shelf has more measured response than the floor. For those of you placing your components on the floor- not a bad way to go.
I am adding two charts to show the resonance point of the preamp and DAC. My DAC weighs 86 lbs. That let me get the fn down to 6 Hz. I think that second, lower frequency peak is my actual finger tap.
I'll do my summary first. The first step to better sound should be to isolate the electronic components from vibration. Vibration comes primarily from the speakers- unless you live in California or Hawaii where ground movements are more severe. But then most people are likely not trying to listen to music during severe ground movement. Who knows, some people might live in an area where traffic causes vibrations up through their floors.
I show in the following charts how the spring footers are effective at isolating the audio electronic components from external vibrations. These spring footers are mostly neutral when it comes to effects on the sound. Now once the components are placed on well isolated shelves, then the next step can be performed- tuning the footers that are on the audio components. I prefer to use the manufacturers footers but that is just me. Others may find various types of footers in various configurations tailor the sound more to their liking. It's an interesting hobby because it has seemingly infinite permutations. Now that I am retired and had time to apply myself to finding some solutions to basic audio problems I'm disappointed in myself that I didn't think of spring isolation decades ago. It was always staring me in the face. End result is clarity, sharper image focus and more detail- gobs of detail but without sibilance.
What I show in the following charts is how these spring footers isolate the audio components from vibration. A spring mass system has a specific resonance point called fn- natural frequency. The ideal resonance point for audio, auto, etc is typically around 3 Hz. Best I can achieve with these spring footers is about 6-7 Hz. Still very good at isolating components. I would not recommend them for Turntables because 6-7 Hz is too close to the Tonearm/Phono cartridge resonance point. In the case of turntables, the isolators need to be 3 Hz. The only way to practically get there is with extension springs. Consider that to drop the resonance point from 6 Hz to 3 Hz requires the spring rate to be reduced by a factor of 4. That is not easy to do with compression springs and still keep the platform stable. But of course the other way to isolate components is with active isolation platforms- a more costly solution but even better isolation performance.
My accelerometer and FFT plots are limited to 50 Hz. That still shows the bass notes in the music finding their way to my component shelf. In fact, the shelf has more measured response than the floor. For those of you placing your components on the floor- not a bad way to go.
I am adding two charts to show the resonance point of the preamp and DAC. My DAC weighs 86 lbs. That let me get the fn down to 6 Hz. I think that second, lower frequency peak is my actual finger tap.
Since I am on a roll I want to mention room vibrations or room response. This is another area I spent some time on. The first picture shows my system in my listening room with the room treatments that I have developed. Behind the big cloth frames are diffusors. My wife didn't like how they looked so I built those cloth frames to cover them. I need to die the cloth- another item on my list. Also see in my room some corner traps and side traps for first reflections. I also have corner traps in those alcoves to the sides. I bring this up because when I was last at HiFi Buys in Atlanta one of the sales techs told me about an app called Impulso. It measures your room response. The chart shown below is the results I got testing my room. The app requires you to pop a balloon at the speaker location while the phone records the reflections at the listening position. The results I got for my room look pretty good. I'm pleased considering the effort I put into it. Give it a try if your audio nervosa can take it. Believe me, I was a bit nervous about this test- enough to make a special trip to the store to find some balloons.
The Impulso app is looking at decay times of your room across the frequency spectrum. Too much room damping and the music can sound dull and lifeless. Too little room damping and the music can sound boomy, muddy and the highs glaring. It seems like a good app to help with optimizing the listening room. What's nice is seeing how the highs, mids and lows are responding separately. btw- let your wife know when you are about to pop the balloon. Helpful domestic tip.
The Impulso app is looking at decay times of your room across the frequency spectrum. Too much room damping and the music can sound dull and lifeless. Too little room damping and the music can sound boomy, muddy and the highs glaring. It seems like a good app to help with optimizing the listening room. What's nice is seeing how the highs, mids and lows are responding separately. btw- let your wife know when you are about to pop the balloon. Helpful domestic tip.
I've been working on vibration management for 30+ years. Any intelligent discussion of the subject has to address two separate issues: 1) isolation from external (floor borne and air borne) vibrations, and 2) draining/dissipating/tuning (if desired) internal component resonances caused by transformers, motors, large caps discharging, etc. (which can be exacerbated by external vibrations). Many devices attempt to do both, but I have not found any that are equally good at both. In my experience the pendulum type decoupling/isolation platforms/footers pioneered by Wellfloat (which don't store energy like springs and are frequency independent) are audibly superior to any spring based solution. I use them under each component combined with a footer that drains/dissipates and tunes internal component resonances. Having tried several dozen different devices/combinations over the years (including the high end ones like Townshend, Stillpoints, and Critical Mass Systems) I have found nothing that matches the performance of Dalby Lignum Vitae footers or (less expensive 2nd choice - ASI Top Line feet) between component and Wellfloat isolation board. Note by the way that every all metal footer I've tried including top tier Stillpoints betrays its composition by adding a subtle hardness to the sound. This won't show up in measurements but is clearly audible, and is as much a "coloration" as the excessive warmth that some wooden feet, improperly deployed, sometimes add. I'm not going to post graphs because I don't do measurements - I trust my critical listening skills.
FYI: https://wellfloat-global.com/技術解説/
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Hello Cellcbern, thank you for that reply. I took a look at the link you posted. Very interesting- your wellfloat isolation platforms are a spring based isolation design. It is a well engineered, compact design. They use leaf springs with cables to suspend the isolated sub base. It doesn't say on their website but I imagine that they achieve a resonance point around the ideal 3 Hz. By suspending the sub base below the springs, the sub base is inherently stable. Where the Townshend speaker isolation platforms tend to make the speakers a bit tipsy due to the use of compression springs, these isolators are applied separately at each speaker foot making the speakers much more stable. It is a brilliant design. Plus, since a speaker rarely has a center of gravity at the center of the cabinet, ie the weight at each speaker corner may not be identical, these Wellfloat platforms likely provide some adjustability. Brilliant.
Just as I was saying, extension springs on some sort of super structure is the only way to get the spring rate low enough to achieve a 3 Hz resonance point and keep the platform stable. The Wellfloat is a brilliant, compact design using low rate leaf springs. Makes me want to try and rig something up like that myself.
PS. A point I was going to bring up sometime: I made some spring isolation platforms for my previous pair of Thiel CS6 speakers. They did a remarkable job of isolating the speakers from the floor but yes, they were a little bit tipsy. I bought a set of IsoAcoustic Gaia footers to try on my Thiel speakers and although they did not completely isolate the speakers from the floor like my spring isolation platforms, they sounded better to me. I kept the Gaia footers and put the spring isolation platforms on my HT Subwoofers. The bass sounds great on them now.
Just as I was saying, extension springs on some sort of super structure is the only way to get the spring rate low enough to achieve a 3 Hz resonance point and keep the platform stable. The Wellfloat is a brilliant, compact design using low rate leaf springs. Makes me want to try and rig something up like that myself.
PS. A point I was going to bring up sometime: I made some spring isolation platforms for my previous pair of Thiel CS6 speakers. They did a remarkable job of isolating the speakers from the floor but yes, they were a little bit tipsy. I bought a set of IsoAcoustic Gaia footers to try on my Thiel speakers and although they did not completely isolate the speakers from the floor like my spring isolation platforms, they sounded better to me. I kept the Gaia footers and put the spring isolation platforms on my HT Subwoofers. The bass sounds great on them now.
SoundKaos copy of the Wellfloat design (link below) - suspended wire - no springs.
Vibra 68
Exactly. The leaf springs are U shaped so they cannot move straight up and down, they move in a rocking motion like a pendulum. That was apparently the design solution they were looking for. First rule of engineering design: If you can’t fix it, feature it.
It’s a good design- nice and compact. It is still a spring/mass system and therefore isolates by not responding to vibrations beyond the system resonance point.
It’s a good design- nice and compact. It is still a spring/mass system and therefore isolates by not responding to vibrations beyond the system resonance point.
See that green bronze plate on the Vibra 68? That’s the spring. It looks like the two SS washers at the bottom of those studs act as springs too. The problem with leaf springs is that the spring rate varies by thickness cubed. That means exacting tolerances are needed on the thickness to keep them within a reasonable, consistent range.SoundKaos copy of the Wellfloat design (link below) - suspended wire - no springs.
Vibra 68
6moons.com
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It is clear from the cutaway drawing that the weight bearing wire in the Sound Kaos footer is suspended from stainless steel structures which are connected to the stainless steel base.
Every mechanical system is made up of springs, mass and dampers. Suspended by a wire? The wire is a spring.
The cutaway I am looking at shows a bronze plate as the platform. The load passes through the bronze plate to those two studs which are mounted to two SS washers. Then the washers are grounded to the base via suspended wires. That makes the bronze plate and the two washers leaf springs. The wire is a spring too but it is a relatively high spring rate. Think of the wires on a musical instrument. They are springs that vibrate at their resonance point when plucked and that resonance point is also proportional to the length, thickness and tension on the wire- as well as the material properties of the wire. Therefore, these footers have potentially vibration response coming from those wires.
The cutaway I am looking at shows a bronze plate as the platform. The load passes through the bronze plate to those two studs which are mounted to two SS washers. Then the washers are grounded to the base via suspended wires. That makes the bronze plate and the two washers leaf springs. The wire is a spring too but it is a relatively high spring rate. Think of the wires on a musical instrument. They are springs that vibrate at their resonance point when plucked and that resonance point is also proportional to the length, thickness and tension on the wire- as well as the material properties of the wire. Therefore, these footers have potentially vibration response coming from those wires.
I disagree. The top plate is never compressed, deformed or stressed the way a leaf (or any) spring would be in the device's operation. It simply moves with the pendulum motion of the suspended wire. Having taken apart the Wellfloat Delta footers this is clear. And whether or not the semantics of things is that a wire is theoretically a spring, these pendulum motion suspended wire devices work differently from the damped coil spring devices that you provided photos of in your system, and as I've said are to my ears audibly superior.
This is news to me but then I’ve been dabbling with vibration mgmt. much less than you. Can you elaborate on why a discussion about vibration mgmt. that does not address both methods lacks intelligence?
I thought the two methodologies were pretty much diametrically opposed in most every aspect???
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