IsoAcoustics Isolation Feet - Does it really make positive effect or fancy accessories

[MattHooper]

I don't think you understand. We can't know. You can't transfer your experience to us.

Yes, I know that’s precisely what I keep saying. It’s an anecdote. The reader can take it as they wish which includes completely rejecting it as informative, for the reasons you are choosing to do so.

I’ve said this before: even when I have provided detailed results of my blind tests, it’s still the fact that the reader will have to judge whether they will take it as a data point or not. Some simply will not, after all, I could’ve made a mistake somewhere that is not evident in what I wrote. Others may have a certain amount of experience in which my test makes sense and they may accept it as a data point.

You can’t force anybody to accept anything.
And so… it’s up to you. And you’ve got good reasons to not pay it much heed.

The data I've seen has convinced me that deliberate isolators beyond something very basic are not, leading me to doubt your stories of easily audible differences.

I've tried these tweaks at home. I've used foam pads to prevent desktop speakers from rattling stuff on my table. The rattling stopped, but the sound did not change.

Then your scepticism makes perfect sense to me. And our own sets of experience will tend to inform how we look at other people‘s claims. You for instance, had the experience of rattling being stopped, but not noticing any audible change. From what you’re telling me I can’t actually know that there wasn’t an audible change using the foam pads . It’s just an anecdote to me, and maybe it was actually audible (if you didn’t blind test to determine this).

So yes, this is why something like measurements can help break these type of stalemates. Which is why I wasn’t offering my experience has anything but an anecdote.
But it’s an anecdote that explains my own particular stance just as yours explains yours.

When I had my speakers on, as I remember, one granite shelf with that shelf spiked into my floor, as much as I was hoping for tighter bass I was really put off by what sounded like more bloated bass. I have my bass torture tracks and the bass just lost some definition, and sounded more like bass nodes sticking out.

The fact that what sound sounded like obviously bloated bass was also accompanied by a new rattling of my speaker grill when certain bass notes hit, and it was repeatable by changing in and out that shelf, made the case for those changes quite compelling. I’m sure you can imagine that at least the type of experience I’m describing, in informal scenarios, could be pretty convincing. That that’s the power of experience.

But of course, while I am more convinced than you are because I had the experience, I also acknowledge that in the big picture I could’ve been mistaken, and doing measurements or a blind test would help rule out variables.

If I could, I would actually like to blind test this. Because at one point, I was using some furniture scissor lifts that allowed me to keep the speakers at the same height and shift different materials in and out. So I guess it’s possible that I could have had somebody switch in the materials in a blind test fashion.

I didn’t have anybody handy at the time to do that unfortunately.

 

[Curvature]

Then your scepticism makes perfect sense to me. And our own sets of experience will tend to inform how we look at other people‘s claims. You for instance, had the experience of rattling being stopped, but not noticing any audible change. From what you’re telling me I can’t actually know that there wasn’t an audible change using the foam pads . It’s just an anecdote to me, and maybe it was actually audible (if you didn’t blind test to determine this).

So yes, this is why something like measurements can help break these type of stalemates. Which is why I wasn’t offering my experience has anything but an anecdote.
But it’s an anecdote that explains my own particular stance just as yours explains yours.

I want to clarify that what I meant was that I can't make these antivibrational tweaks work beyond dealing with completely normal and obvious problems. It's not like applying EQ or changing the volume or listening from the kitchen. The way some people relate their experiences, it should be as easy as that to pick out a difference.

Otherwise I agree with you.

There's another side to this as well, and that's the buying advice we give out on the forum. These expensive footers and platforms are "not recommended". Rattles can usually be diagnosed and fixed cheaply.

 

[Purité Audio]

Expensive trinkets for the gullible.
Keith

 

[MarkS]

The thing that annoys me is that so many floorstanding speakers now come with ugly feet poking out.

 

[Curvature]

The thing that annoys me is that so many floorstanding speakers now come with ugly feet poking out.

View attachment 464902View attachment 464904

I kind of like them. They give strong "alien invasion" vibes.

 

[Count Arthur]

 

[Anton S]

The thing that annoys me is that so many floorstanding speakers now come with ugly feet poking out.

View attachment 464902View attachment 464904

Depends on the design. Wide, squat speakers typically aren't equipped with them. But outriggers do add stability to tall, slender, often top-heavy designs to help prevent accidental tipping. A secondary benefit is the added protection against impact damage from rabid vacuum cleaners and such.

 

[MattHooper]

Depends on the design. Wide, squat speakers typically aren't equipped with them. But outriggers do add stability to tall, slender, often top-heavy designs to help prevent accidental tipping. A secondary benefit is the added protection against impact damage from rabid vacuum cleaners and such.

All true!

I think the outrigger feet can be done tastefully. I like some of the Marten designs;

I also like the look of a loudspeaker - especially if it’s slender - that has a dark base (not a huge fan of the looks of the speaker, but the base illustrates what I’m talking about):

There is something a little bit more deliberate and designed-looking when a speaker has a base like this rather than the speaker looking like it’s been plunked directly on a carpet or floor or whatever.

I think the Sonus Faber marble bases can look quite nice (depending on the cut of marble one gets with the speaker):

My speaker is very slender so it required outriggers. But I put them on a granite base.
It makes the speakers incredibly sturdy (especially because the isoacoustic feet on the back suck on to the granite firmly):

 

[knownothing]

I don't think you understand. We can't know. You can't transfer your experience to us. If you had made measurements, we could have examined the situation together and you could have examined it yourself from the perspective of a third party.

One of the points of the scientific method is access to perspectives outside of one's own. This is why anecdotes are not useful. The value is not in what happened, it's in the investigation. It comes down to the reproducibility of experience, being able to make a specific event occur many times by arranging the circumstances correctly, making that experience consistent across many people, and decoupling, if you will, the experience from the person.

If you and others in this thread who tweaked their way out of vibrational problems don't investigate the event enough to be sure (remember, the goal is not to convince only yourself), then we are stuck at not being able to know. It's like a person who overdrives the inputs, causing clipping, and buys a new amplifier instead of turning down the gain. Perhaps that amp had lower gain by default, and the problem vanished. The solution was not found in some kind of unsaid qualities of either amp, but in a definable issue of the signal chain.

Vibration and sound are mathematically related. Vibration always has to be taken into account given that sound energy travels through all mediums. But we have known thresholds that this energy must meet to be audible or felt.

The only question is if expensive isolators, heavy platforms, special stands, and the rest of it are necessary. The data I've seen has convinced me that deliberate isolators beyond something very basic are not, leading me to doubt your stories of easily audible differences.

I've tried these tweaks at home. I've used foam pads to prevent desktop speakers from rattling stuff on my table. The rattling stopped, but the sound did not change.

I have seen attempts to measure differences. FR changes are commonly corrupted because of changes in speaker or mic position. Decay changes, if they even occur, are small and subject to masking or are difficult to assess because of room noise. Well, in the Isoacoustics article I posted and analyzed, we have laser interferometry in an anechoic chamber. I already posted my thoughts on what could be improved to make the experiment more comprehensive. It's a near ideal demonstration, by the creator of the product, that the product is unnecessary.

“It's a near ideal demonstration, by the creator of the product, that the product is unnecessary.”

Please explain again how the data presented by the creator of the product demonstrates the product is unnecessary. I suggest your claim or inference that the measured differences are “insignificant” and inaudible is only an assumption.

kn

 

[Curvature]

“It's a near ideal demonstration, by the creator of the product, that the product is unnecessary.”

Please explain again how the data presented by the creator of the product demonstrates the product is unnecessary. I suggest your claim or inference that the measured differences are “insignificant” and inaudible is only an assumption.

kn

https://www.audiosciencereview.com/...rs-whats-happening.20446/page-28#post-2352829

 

[knownothing]

https://www.audiosciencereview.com/...rs-whats-happening.20446/page-28#post-2352829

This recapitulation of your original point does noting to address this issue brought up in the cited article:

“3. Energy Reflected Back into the Speaker
When vibrations travel from the speaker into the supporting surface, they don’t just dissipate. They are also conducted back into the speaker cabinet, similar to hitting a section of pipe bolted to a concrete wall: the energy travels down the pipe, hits the wall, and then an inverse wave is conducted back along the pipe. This back-and-forth energy exchange is conducted back into the speaker enclosure, resulting in smeared sound, less articulate bass, and reduced clarity. Any artefacts that are common in both channels are perceived to be in the middle and result in a collapsed and two-dimensional phantom image. Managing internal reflections is essential to preserving clarity, precision, and spatial definition. The artefacts are timing variations re-entering the speaker enclosure and are not revealed during sweep frequency testing in the anechoic chamber.”

Which is, by the way, are the elements of reproduced sound that were detectable and benefiting from the isolation products reported from the ABX test in the YouTube video discussed earlier in the thread. The difference between the changes in measured physical disturbance (velocity) and frequency sweep you cite is an indictment of frequency sweeps as a tool to separate out issues related to timing and localization of sound, not an indictment of the efficacy of the product.

kn

 

[Curvature]

“3. Energy Reflected Back into the Speaker
When vibrations travel from the speaker into the supporting surface, they don’t just dissipate. They are also conducted back into the speaker cabinet, similar to hitting a section of pipe bolted to a concrete wall: the energy travels down the pipe, hits the wall, and then an inverse wave is conducted back along the pipe. This back-and-forth energy exchange is conducted back into the speaker enclosure, resulting in smeared sound, less articulate bass, and reduced clarity. Any artefacts that are common in both channels are perceived to be in the middle and result in a collapsed and two-dimensional phantom image. Managing internal reflections is essential to preserving clarity, precision, and spatial definition. The artefacts are timing variations re-entering the speaker enclosure and are not revealed during sweep frequency testing in the anechoic chamber.”

The energy reflected back into the speaker is measured and displayed in that graph. It does not venture into unmeasurable places. The impacts are direct. They are just very small.

Vibration and sound are mathematically related. If you can measure the vibration you can convert to a pressure value and vice versa.

What I'm saying is that the measured levels are very low. If you have know a little of the math that underlies logarithmic dB calculations, then you'll understand why the contribution to frequency response is so low, and why my conclusion is what it is, since frequency response is the most significant measurable parameter that bears on audibility.

If you like I can re-explain my comments from my earlier post that contextualize the above.

 

[MAB]

This recapitulation of your original point does noting to address this issue brought up in the cited article:

“3. Energy Reflected Back into the Speaker
When vibrations travel from the speaker into the supporting surface, they don’t just dissipate. They are also conducted back into the speaker cabinet, similar to hitting a section of pipe bolted to a concrete wall: the energy travels down the pipe, hits the wall, and then an inverse wave is conducted back along the pipe. This back-and-forth energy exchange is conducted back into the speaker enclosure, resulting in smeared sound, less articulate bass, and reduced clarity. Any artefacts that are common in both channels are perceived to be in the middle and result in a collapsed and two-dimensional phantom image. Managing internal reflections is essential to preserving clarity, precision, and spatial definition. The artefacts are timing variations re-entering the speaker enclosure and are not revealed during sweep frequency testing in the anechoic chamber.”

Which is, by the way, are the elements of reproduced sound that were detectable and benefiting from the isolation products reported from the ABX test in the YouTube video discussed earlier in the thread. The difference between the changes in measured physical disturbance (velocity) and frequency sweep you cite is an indictment of frequency sweeps as a tool to separate out issues related to timing and localization of sound, not an indictment of the efficacy of the product.

kn

No, that video you posted earlier contained null measurements - no change in sound. What followed was an allegation that some manner of blind test was performed. It got serially debunked by multiple members, including Amir. Sorry, the author of the video wasted too much time trying to make a microphone burn video, never told the full story. I am a skeptic, if someone obscures methods and data, the hide tells more than their reveal.

Your video demonstrated the opposite of what you claim, and is another example of a demonstration that the products are unnecessary.

 

[knownothing]

What I'm saying is that the measured levels are very low. If you have know a little of the math that underlies logarithmic dB calculations, then you'll understand why the contribution to frequency response is so low, and why my conclusion is what it is, since frequency response is the most significant measurable parameter that bears on audibility.

Speakers that measure very similarly in terms of frequency response can nevertheless sound different in the listening room. What distinguishes a modest speaker with a relatively flat measured frequency response from a high end speaker with a similarly flat measured frequency response is often subtle changes in representation of timing and space in how the music is represented that can also affect timbre.

These slight differences result from the interaction of the technology and materials used in the drivers and crossover, the cabinets and the room (and the listeners ears). Different manufacturers have different philosophies for how they approach the relationship between the drivers and the cabinets with for example, Harbeth on one end of the spectrum and YG Acoustics on the other of cabinet “liveliness”. In all cases, speaker designers tune their driver/crossover/ cabinet designs by ear to get the final results they ultimately put on the market. Nobody selling into the high end market looks at a frequency or waterfall chart and says “nailed it - no need to listen”.

And there is no logical reasoning to suggest that the same process of tweaking the sound and managing vibrations in the listening room should end at the speaker cabinet. Nor that frequency response curves are the final arbiter of soundstage and timing accuracy as experienced by a listener in their room, in their seated position with their ears and brain and their accompanying gear.

Hifi is a systems problem, and our reductionist measurements tell and reveal only a part of the whole story and experience. The trick is the wade through the marketing noise to get to your individual “truth”, and that requires various investments of time and money. Would that all satisfaction spring from a frequency diagram.

kn

 

[NTK]

“It's a near ideal demonstration, by the creator of the product, that the product is unnecessary.”

Please explain again how the data presented by the creator of the product demonstrates the product is unnecessary. I suggest your claim or inference that the measured differences are “insignificant” and inaudible is only an assumption.

kn

I did a back-of-the-envelope calculation to see roughly what the SPL is from the measured surface velocities, and it is at most 21 dB SPL. It is evident from the unnoticeable differences in the measured anechoic FR curves that the effects are not going to be significant. Measurement mics can easily detect differences well below 1 dB. Humans can't.

Post in thread 'Gaia Isolation anything in this?'

Oct 19, 2024

Regarding the IsoAcoustics test results, here are some simple "back of the envelope" calculations. Below are the IsoAcoustics GAIA II NRC Canada test results.

The highest peak in the surface velocity with spikes is ~7.8e-6 m/s at ~280 Hz. Using the formula given by Siegfried Linkwitz (source) shown below, we can come up with some estimates of the resulting dB SPL.

Assume (1) the dimensions of the panel that was vibrating is 1.0 m × 0.5 m = area of 0.5 m² (it is assumed that the...

• NTK

• 

Speakers that measure very similarly in terms of frequency response can nevertheless sound different in the listening room. What distinguishes a modest speaker with a relatively flat measured frequency response from a high end speaker with a similarly flat measured frequency response is often subtle changes in representation of timing and space in how the music is represented that can also affect timbre.

No two speakers of different designs measure "very similarly". Don't forget for them to "measure similarly", their sound radiation characteristics need to "measure similarly" at all angles.

Hifi is a systems problem, and our reductionist measurements tell and reveal only a part of the whole story and experience. The trick is the wade through the marketing noise to get to your individual “truth”, and that requires various investments of time and money. Would that all satisfaction spring from a frequency diagram.

Sort of true. But, to quote Dr Toole:

I have said, and I repeat: Frequency response is the most important parameter in any audio component. If it is wrong, nothing else matters.
...

 

[Gitfiddle]

Speakers that measure very similarly in terms of frequency response can nevertheless sound different in the listening room. What distinguishes a modest speaker with a relatively flat measured frequency response from a high end speaker with a similarly flat measured frequency response is often subtle changes in representation of timing and space in how the music is represented that can also affect timbre.

I think this is a good point, but...

Timbre is the part of music where measurements probably matter the most. In room measurements can show resonances, frequency response, distortion, and so on; and then used to correct problems with EQ and placement.

If timbre is getting significantly effected by a speaker itself, I wouldn't call it a high end speaker! If that is going on in your system, some gimmick feet are the least of your worries. Accuracy and transparency is key to timbre.

As Merriam-Webster defines Timbre:

: the quality given to a sound by its overtones: such as
a
: the resonance by which the ear recognizes and identifies a voiced speech sound
b
: the quality of tone distinctive of a particular singing voice or musical instrument

A great example of timbre is hearing the differences between the different guitars used in Stairway to Heaven.

 

[MAB]

I did a back-of-the-envelope calculation to see roughly what the SPL is from the measured surface velocities, and it is at most 21 dB SPL. It is evident from the unnoticeable differences in the measured anechoic FR curves that the effects are not going to be significant. Measurement mics can easily detect differences well below 1 dB. Humans can't.

Post in thread 'Gaia Isolation anything in this?'

Oct 19, 2024

Regarding the IsoAcoustics test results, here are some simple "back of the envelope" calculations. Below are the IsoAcoustics GAIA II NRC Canada test results.

The highest peak in the surface velocity with spikes is ~7.8e-6 m/s at ~280 Hz. Using the formula given by Siegfried Linkwitz (source) shown below, we can come up with some estimates of the resulting dB SPL.

Assume (1) the dimensions of the panel that was vibrating is 1.0 m × 0.5 m = area of 0.5 m² (it is assumed that the...

• NTK

• 

No two speakers of different designs measure "very similarly". Don't forget for them to "measure similarly", their sound radiation characteristics need to "measure similarly" at all angles.


Sort of true. But, to quote Dr Toole:

This is consistent with yet another video made by a manufacturer posted in the 'springs under my speakers' thread. The video that shares data that proves these isolation products are irrelevant to sound reproduction. By the videos own data, they bound the problem to about 25dB in-room. Aside from measuring with an accelerometer, placed in varying places run to run, finding tiny differences in the vibrational spectra. They also show there is no change in sound:

Post in thread 'Springs Under My Speakers: What's Happening?'

Jul 11, 2025

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...

• MAB

• 

They even provide an estimate of cone motion due to all of this, their own estimate is equivalent to 25dB SPL :

Post in thread 'Springs Under My Speakers: What's Happening?'

Jul 12, 2025

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...

• MAB

• 

It's absurd. These videos keep dishing up serial helpings of nothing-burgers, yet try to rewrite the results.

 

[Curvature]

Speakers that measure very similarly in terms of frequency response can nevertheless sound different in the listening room. What distinguishes a modest speaker with a relatively flat measured frequency response from a high end speaker with a similarly flat measured frequency response is often subtle changes in representation of timing and space in how the music is represented that can also affect timbre.

Not... really.

Here's how to think about it:

1. What many people present as frequency response for speakers, the 0 degree or on- axis response, when the microphone is directly facing the speaker: https://www.spinorama.org/speakers/Genelec S360/Genelec/vendor/On Axis.html
2. Horizontal 360 degree frequency response: https://www.spinorama.org/speakers/Genelec S360/Genelec/vendor/SPL Horizontal Contour.html
3. Vertical 360 degree frequency response: https://www.spinorama.org/speakers/Genelec S360/Genelec/vendor/SPL Vertical Contour.html
4. Spherical frequency response:

   https://imgur.com/a/Ae4ssAy

For the rest, it all appears in frequency response. Without exaggeration. What you hear is the pressure at your eardrums. Pressure per frequency is "frequency response". Whatever aspects manufacturers include in their designs show up. The impacts of changes in drivers, cabinets and so forth show up. The impact of the room can be modelled if you have comprehensive anechoic data, as above, and know your room dimensions. Or room impacts can be measured with a microphone.

If you know the background well enough, these graphs are interpretable and meaningful.

 

[Curvature]

I think this is a good point, but...

Timbre is the part of music where measurements probably matter the most. In room measurements can show resonances, frequency response, distortion, and so on; and then used to correct problems with EQ and placement.

If timbre is getting significantly effected by a speaker itself, I wouldn't call it a high end speaker! If that is going on in your system, some gimmick feet are the least of your worries. Accuracy and transparency is key to timbre.

As Merriam-Webster defines Timbre:

: the quality given to a sound by its overtones: such as
a
: the resonance by which the ear recognizes and identifies a voiced speech sound
b
: the quality of tone distinctive of a particular singing voice or musical instrument

A great example of timbre is hearing the differences between the different guitars used in Stairway to Heaven.

Timbre is the subjective side of sound (psychoacoustics). Frequency response is the physical side (acoustics).

Historically we have tended to associate timbre with a particular source, like an instrument. The thing has a particular timbre. But fundamentally the word refers to what we hear. How the instrument performs, how it radiates sound into the world, without reference to a particular listener, that's frequency response.

Here we get into perceptual limitations of what speakers are able to do, whether they are convincing or not. They are reproducers, middlemen, messengers. A lot of this has to do with the quality of the recording. The physical characteristics of speakers also impact how well this can be done, and those things we can reliably measure and discuss. What aspects of measured physical quantities matter and actually impact subjective timbre have been studied as well through controlled listening tests.

 

[Curvature]

For the rest, it all appears in frequency response. Without exaggeration. What you hear is the pressure at your eardrums. Pressure per frequency is "frequency response". Whatever aspects manufacturers include in their designs show up. The impacts of changes in drivers, cabinets and so forth show up. The impact of the room can be modelled if you have comprehensive anechoic data, as above, and know your room dimensions. Or room impacts can be measured with a microphone.

If you know the background well enough, these graphs are interpretable and meaningful.

I want to clarify that hi-fi makes lots of claims without providing proof. It is often said that more care and work is put into speakers by hi-fi brands and not mass-mass market or professional or small brands. But where's the proof? Is it in how heavy an enclosure is vs. another? Or how exotic driver materials are? That one driver is made from paper, another ceramic and another beryllium? The proof is what matters.

I watched Moneyball recently and I read the original book. What struck me was how similar the approach on ASR, for some, is to the statistical approach of evaluating players and optimizing a team based on results. If you have the right stats, you can make the right calls.

Same thing here. What is the actual impact of any given design decision compared to another? It's measurable, whatever it is, and the result is interpretable.

Is absolutely everything known about sound and speakers? Not even close. From another thread: https://www.audiosciencereview.com/...th-human-perception.63940/page-4#post-2348585

What we have, from the science, is a set of guides that let us examine what a loudspeaker can do and come to reasonable judgments about how it will sound under a variety of circumstances.