Do you isolate your gear?

Todd Anderson

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At CAF 2017 I heard a puck isolation system demo in Daedalus Audio's room. The A/B comparison involved pucks under a standalone DAC. The soundstage (with pucks) was open and focused...without pucks it appeared to narrow and collapse somewhat.

I currently do not have isolation feet/products on any AV gear... I curious to read about other's experiences.
 

Tony V.

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I'm still feel this whole "sound isolation dampeners" thing a little to snake oil for me. I get it on things like turntables but other items like speakers and source devices like receivers just don't make sense. I do not trust many of these A/B comparisons unless I personally am involved in the setup of both systems to ensure there're is not "monkey business" going on
 

Todd Anderson

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You know... I’d normally agree. But I heard it with my own ears.
 

Tony V.

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Are you sure they had not altered the sound from the one without pucks? My spidy senses are tingling
 

Todd Anderson

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I watched him remove the pucks... play a clip... replace the pucks.. replay the same clip.

Sounded different to me
 

Todd Anderson

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Sounds crazy, right? Just reporting what I heard
 

Tony V.

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Did the DAC have tubes in it? Tubes are subseptable to vibration. That's all I can think of
 

Todd Anderson

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I don’t think so... but to be honest, Tony... not sure
 

Todd Anderson

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Vibration can be introduce to other systems... I was just surprised to hear any difference in the same system
 

Tony V.

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I don't doubt you heard a difference. Would have loved to be there to listen myself. Never been to any sort of large audio show where these demos happen. Some day...
 

Todd Anderson

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It was a fairly benign demo... we were listening to Daedalus’s new speakers and someone asked about their isolation pucks. Same system. Same speakers.

Tony, believe me... this kind of tech is not something I normally subscribe to. Although, I’ve heard differences with Isoacoistic products and have some in for review. Very curious to see what I find...
 

Matthew J Poes

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My equipment rack has silicone isolation discs to isolate each shelf. Then my equipment is hit or miss.

My Onkyo reciever is stock feet.

Sony Bluray player is sorbathane isolation feet

Record player is spikes sitting on a composite of felt/cork/felt with a visco-elastic glue holding it together.

All my amplifiers are on feet made of similar composites of rubber, cork, and felt.

I also have a ceramic bearing isolation system and a magnetic isolation system not in use. Both were given to me.

My own opinion is that sensitive gear like record players and Blu-ray players can benefit a bit. It makes sense that it could help but also is something I felt I could clearly hear. With speakers I always felt it made sense too and I keep my speakers on mass loaded stands with spiked feet. With everything else I've been more uncertain of the effect.

For what it's worth clock oscillators in DACs are sensitive to vibrations. An isolation system could benefit a dac due to that. Lots of reason to argue it shouldn't matter as the effect would be small and likely very low in level, but then, not like it's extensively tested. Most good Dacs do try to isolate the circuit boards and clocks from vibrations. That doesn't mean more can't be better.

I've had many times in my life where I read about concepts that shouldn't be audible. That sound like pure science fiction or delve into a level of perfection that can't be audible. Yet hear differences clear as day. When Skip demoed his Northstar dac we switched back and forth between 5.8 MHz DSD and 384khz pcm. The noise in both of these scenarios should have been well out of the audible range. They should have sounded identical. In a noisy demo environment it was clear as could be to all of us on the first track that 384pcm was superior sounding. Later with another track we got to fiddling and switched again and that time Skip and I commented that the DSD sounded better.

Sometimes you just have to listen with your ears and trust what they are telling you. If it's all snake oil placebo then the worst that happened is you spend money on something that helps you enjoy your music more through psychological trickery. It's not such a big deal. I'm very much an objectivist but I listen with my ears first.
 

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The only things I have on isolation stands are my Emotiva Airmotiv 6s powered monitors and the PB16-Ultra Subwoofer. It made a noticeable difference in the sound on the monitors, and I'm sure it did so on the sub but I never did an A/B comparison
 

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If this was done sighted, then nothing much can be taken away from it. "I heard it with my own eyes" oops. I mean "ears" :p. These scientifically sketchy devices are typically debunked with blind testing. Which is why they're never tested blind during demos.

Sighted bias cannot be discounted, particularly when the scientific basis for the change is highly suspect.

Just my opinion. :greengrin:
 

Matthew J Poes

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If this was done sighted, then nothing much can be taken away from it. "I heard it with my own eyes" oops. I mean "ears" :p. These scientifically sketchy devices are typically debunked with blind testing. Which is why they're never tested blind during demos.

Sighted bias cannot be discounted, particularly when the scientific basis for the change is highly suspect.

Just my opinion. :greengrin:
I think we need to be careful not to overstate what science has done here or can do. You are correct when you say there aren't many good studies of such devices, but to say it is because they wouldn't hold up to scrutiny is a step too far. I think there are no good studies because the scientific community has better things to do. If there is no interest, people don't study it. That isn't the same as saying there is no science behind the idea or that they aren't studied because they are pseudo-science.

Let's also not forget the ever present mantra in the scientific field (especially the field of human perception) the absence of evidence is not evidence for absence. In other words, just because a study did not support the hypothesis doesn't mean the hypothesis is wrong, and we can't say that. You will note in general that good scientists would never use the phrase: Science has proven that vibrations don't effect electronics" or "Vibration isolation devices are proven not to improve sound." That is because a) this hasn't really been studied, and b) science could never draw that conclusion. All we can say is that studies to date have not provided evidence to support this notion.

Now as to the actual science of vibration isolation on electronics, this has been studied, though minimally for audio. In the days of record players and tapes it was well understood (and studied) that vibrations would cause distortions in the output of the electro-mechanical device. Isolation of the devices thus would reduce this distortion and improve sound. As such, high quality record players and tape players were built to isolate the sensitive electronics from vibrations. The fact that record players changed to be massive instead of isolated was more due to a realization that the spring/mass isolation system used would fix one problem and create another. Which is worse? Who knows, again, the field lost interest with the advent of digital and serious scientists didn't ever bother to test. The fields that did test this are too different to draw conclusions (such as imaging sciences which isolate microscopes for clearer images).

Digital reproduction systems also use vibration isolation and active counter-measures to avoid the negative effects of digital decoding in an vibrating environment. Again, these devices contained what was seen as adequate to do the job, and the advent of modern memory based playback eradicated the issue completely.

Crystal oscillators are also problematic in vibrating environments, this used to be a big issue in the 80's and 90's, but modern electronics used miniature oscillators that are so different that vibrations no longer have the same effects they used to. In fact, all electronic circuits that used to be impacted by vibrations are much less so today due to their integrated nature. In general, it is my understanding that engineers no longer feel that modern electronics are much effected by normal environmental vibrations and so no longer take much effort to address it. However, discrete electronics may still suffer some issues. Extreme vibrations can cause oscillations in circuits that are poorly isolated and of extremely wide bandwidth. While the oscillation would be of very high frequency, these oscillations are known to have an audible effect on the sound we can hear.

The other thing I would point out is that a number of individuals on forums have "published" their own studies of the effects of such devices using inappropriate methods of very low sensitivity to "prove" that such devices don't work. These are as bad as sighted listening tests (if not worse) because they give an illusion of validity and precision that simply isn't there. The same is true of speaker isolation. I've found a few such studies that clearly were not done right. For example they used a low quality measurement microphone of limited bandwidth mounted to a cheap and short microphone stand. That means the shadow of the mic and stand is in the measurement, which is a problem. In one study they took multiple measurements and averaged them, which is the incorrect way to assess a difference. Instead a statistical analysis of the deviation needed to be done (and wasn't). They also relied on measurements taken at a single location and looked at the steady state, rather than effects over time. Since we expect isolation devices to largely impact decay, that would be what matters, and the analysis of decay cannot and should not be done visually. Again, a measurement of the change in rate of decay was needed. The end conclusion is really this, no good studies of this exist and probably never will. They won't exist because nobody cares enough to bother, it isn't of enough significance to merit real research.

What this all means is we can't make a scientific argument for or against any of this as there is no science to be argued. We can say that we see no reason for such devices to work, we can try to draw analogues from related research, but to outright say that science has or would prove them ineffective isn't a fair assessment. It makes me nervous when we start to overstate the science because it both waters down the real science and takes away from the fun of the hobby.

I'll have to go back to pull up the article, but one clear example (to me) of where this could go very wrong is a common view that a speaker's enclosure has little effect on sound quality of a speaker (or objective performance) if the enclosure is made massive enough. Most people feel that for a full range speaker enclosure, we want big thick and massive. In fact, there is good science here, a good amount of legitimate research has examined sound re-radiation through speaker enclosures. What they found was that in sufficiently designed studies a few things are found to be true. They add distortion to the speaker, linear distortion is very small/minor. Non-linear distortion is more significant and more likely to be audible. Since the direct testing of enclosure distortion would be too uncontrolled, we need to look instead at thresholds of distortion detection. The distortion that was added was largely higher order in nature (though distortion was added across the board) and odd order in nature. The amount added exceeded the thresholds for these kinds of distortion, so we would expect them to be audible. I feel fairly certain (this is my conjecture and not science) that this distortion and this effect generally could not be measured easily by an average DIYer on their own. That doesn't mean the effects are too small to be audible because, as I mentioned, in properly controlled study conditions they could measure it and its level exceeded our distortion thresholds for audibility, so it should be audible (they didn't test that, again, it would be really hard to test, scientists usually test distortion by artificially adding it to a clean signal to ensure proper control).
 

gooddoc

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I understand the overall point you're trying to make. I edited my post as I don't think it contributed to a good discussion on this topic.
 
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gooddoc

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@Matthew J Poes My post couldhave come off as confrontational. I just want to be clear it was not. I have been involved in many of these types of discussions over the years and have seen these discussions become very contentious.

I truly respect the opinions of everyone, regardless of whether I agree with them or not. I've become comfortable having an opinion on what I consider to be devices that fall into the near magical category in their method of operation.

That DOES NOT mean I feel that all things that can't be proven to a reasonable degree of certainty are bogus. But I do need some believable hypothetical mechanism to get on board.

I will bow out of this discussion at this point because I honestly don't want to be taken the wrong way as I have some fairly strong viewpoints about some of these things. :)
 
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Matthew J Poes

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I understand the overall point you're trying to make. But to say that nothing can be proven definitively - which absolutely nothing on this world that we live in can be - so therefore no reasonable assumptions can be made about the veracity of a claim, is taking it too far in my opinion. I could make that claim about any thing, and use it as a defense to say: prove me wrong.

In fact, it is the common argument used by the charlatans of this industry.

"I'll have to go back to pull up the article, but one clear example (to me) of where this could go very wrong is a common view that a speaker's enclosure has little effect on sound quality of a speaker (or objective performance) if theenclosure is made massive enough. Most people feel that for a full range speakerenclosure, we want big thick and massive"

The above is not a good example in comparison to the topic of this thread. A reasonable person could argue about the potential audibility of electro-mechanical transducers producing vibrational energy in an enclosure.

But I'm extremely curious what the source of vibration in a hotel room or typical residential space that could possibly account for an audible change in a solid-state device. And even if you could point to a potential source of vibration significant enough, I still don't believe that the device could eliminate enough of it to make any audible change. It's simply a bridge too far.

You clearly have a science background, and if you choose to take the position that no position can be taken, then that is your choice.

For me, if I can come up with no rational reason why a device could possibly work, then I dismiss it. I realize there could be times where I am incorrect, but I'm quite confident the long odds are in my favor.
I think you misunderstood a little of what I said. In science, the scientific method can prove things as true or not, to a point. The issue is a little different. When it is not possible to directly measure something and we have to rely on something like human perception, then we use indirect measures. An ABX test is an indirect measure of the audibility of an effect. A direct measure would be some way of going into a person's brain and seeing that the brain is fully responding to the effect as we KNOW it would in the presence of the effect. A whole lot of impossible stuff there. Instead we rely on a statistical model that tests against the null hypothesis. In such a statistical test we must make a bunch of assumptions. The first is that it's possible that the null hypothesis is true. This of course could be wrong (so it's possible for instance that whatever we establish as our null hypothesis, which we try to disprove, is neither true nor false). There are a number of other assumptions we also make, and all of these assumptions must hold true for a statistical test to valid. These include things like our sample is normally distributed, that errors are normally distributed and non-correlated with each other, etc. In general (my Stat's colleagues may shoot me for saying this, but whatever, it's mostly true) we actually can make these assumptions. When we run our tests however, the results never accept the null hypothesis. They reject or fail to reject. When we fail to reject what we are saying is that we didn't provide any evidence to disprove the null hypothesis (which is our goal). Now we can't assume that as the same as accepting the null hypothesis is true because there are lots of reasons why we would be unable to provide such evidence. Our measurements may be too insensitive (The ABX duration was too short or the listeners of too poor hearing or the content too colored). Our test may not have caused the problem we are trying to alleviate (i.e. it is possible that an isolation device addresses an issue that never showed up in the experiment). You get the pictures, lots of reasons why we didn't come up with said evidence.

As a result of this uncertainty and the test we are actually performing, we can conclude one of two ways, either we provided evidence to reject the null-hypothesis (which still could be a fluke, statistics still allow for unusual results and with enough samples, the probability that this result would show up 5% of the time in 100's of trials can and does happen). The other conclusion can be that we failed to reject the null hypothesis. The evidence we provided doesn't prove anything, that's the actual conclusion of such a scenario. Now let's just say that this was a pretty big study, 1000 participants with 15 ABX trials each. Let's say we repeated this study 100 times, but each time we tweaked our method of measurement to assure we were getting more and more sensitivity in the measurement. If we always got the same result in all 100 studies, and we have solid evidence that our method of measure was reliable, valid, and sensitive enough to pick up the effect, it's fair to conclude that we are unlikely to ever provide evidence of a benefit. Further, that we can make life choices like not using such devices. This is because the preponderance of evidence would not support a conclusion that these devices work. We didn't prove they don't work, but that is a lot of good studies showing no effects.

It would be an over-statement to say that scientists don't believe they can ever draw any conclusions, but no good scientist would ever claim they fully proved or disproved something, as that isn't how our approach works. There is too much uncertainty. We can characterize this with precise measurement. For example, I can actually measure the sensitivity of a test and I can predict with reasonable accuracy what sensitivity level is needed to detect an effect given that I fully understand what effect I'm looking for.

I want to preface this next statement by saying I am not claiming that isolation devices work or that they isolate against the noise I'm about to describe. I'm also not claiming that such noise causes problems with circuits. As I stated above, most modern solid-state electronics do not have performance problems caused by vibrations anymore, especially those using integrated circuits.

As for what noises exist, houses actually have far less noise than hotels. Hotels use commercial HVAC and plumbing systems which use a lot of big motors. Blowers, air recirculation fans, water recirculation, etc. The ducts are larger as is the plumbing This causes A LOT of low frequency noise that we actually don't notice because its so low as to be largely in our insensitive area. In domestic spaces you have this as well, just to a lesser degree. This is one reason we see a rising LF noise floor in most spaces. When you rate a rooms noise coefficient there is an allowance for a rising low frequency floor since it always occurs and isn't too bothersome. Again, how that would effect a solidstate circuit I don't know. They aren't known to be microphonic anymore. Studies done decades ago showed that transistors largely don't show the development of any voltage differential in the presence of low frequency noise, so I don't see a good reason for that. Oscillators were generally well isolated to begin with and early digital circuits (where this was an issue) had so many other problems, like high jitter, high noise floor, etc. that I don't see is as being a big issue. Today, modern digital circuits are near perfect.

I will say (and to claim this as audible is a major step too far), we are now getting to a point with circuits where measurement of said circuits are showing them to be so low noise that they sit at the residual of the measurement device. There are $100 dac's that are near the limit of an AP measurement system. Benchmark Audio DACS, SPL Dacs, etc. all sit at the residual level, their true noise can't be measured. It has been noted by some that truly measuring the noise is hard because wire orientation, hitting the wire during the measurement, a laptop fan too close to the device, etc. all raise the distortion level. It shows that technically yes small vibrations and noise can increase distortion, but we are talking about going from .0000001 to .00001, and no way anyone is going to hear any of that. John Atkinson even found with the Benchmark AHB1 that his test cable added significant distortion to the measurement (Mind you an audiophile cable was not needed to fix it, he had to go with a specially constructed cable using a more solid speakon connector). Again, neither scenario would have been audible, but it goes to show a) how low noise has gotten, and b) that there must be something going on at this very low level of noise. I would not call this evidence for isolation devices, just evidence of the effect of vibrations, positioning, and even cable connections on distortion performance.
 

Matthew J Poes

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@Matthew J Poes My post couldhave come off as confrontational. I just want to be clear it was not. I have been involved in many of these types of discussions over the years and have seen these discussions become very contentious.

I truly respect the opinions of everyone, regardless of whether I agree with them or not. I've become comfortable having an opinion on what I consider to be devices that fall into the near magical category in their method of operation.

That DOES NOT mean I feel that all things that can't be proven to a reasonable degree of certainty are bogus. But I do need some believable hypothetical mechanism to get on board.

I will bow out of this discussion at this point because I honestly don't want to be taken the wrong way as I have some fairly strong viewpoints about some of these things. :)
I didn't take it as confrontational and I hope you don't take mine as confrontational.

The believable hypothetical mechanism is actually the key to an initial hypothesis development and the basis for a test. If we don't have a good reason for why something works and how it works, what are we to test? My current project at work is actually involving the teaching to scientists of how to do a better job incorporating this into the initial planning of a study. What I do deals more with psychology and health than electronics, but human subject experiments don't exactly vary in method, nor does the scientific method change with field of study. It's really common with human subject experiments to develop a study that has so many variables there is no way to know what is going on. Such problems can raise either Type 1 or Type 2 errors in the statistics and there isn't a lot that can be done about it. We need to go back to the study design itself and figure out what we are measuring and how.

I recently attended a statistics conference on Bayesian methods that I think would drive you (and probably most people) mad. The end conclusion was that we should all adopt Bayesian methods into our work more readily as it helps us draw more accurate conclusions, which are in fact less conclusive. We are more certain of our uncertainty.
 

gooddoc

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Well said Matt, and I appreciate your expertise in this area. I agree with all you have said and my response was really quite a few levels down the ladder :). The typical enthusiast needs to evaluate whether a product is worthy of their hard earned dollars, and that decision is hampered in most instances by great uncertainty and paucity of data. General principles and "seat of the pants" probability are about all that is available to most, and the device that was the topic of this particular thread felt a bit like a load of you know what in the "seat of my pants" :).

But all just my opinion :).
 

AudioThesis

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I won't pretend to have read everything above, but these devices are all about reduction in noise - always a good thing. I'll share my experiences with you guys.

My first foray into this was dynamatting the inside of my Pioneer BDP-51fd. When I did so, there was more clarity to the sound AND the picture, believe it or not, had less noise to it on my 120" projection. After doing that, I decided to take the plunge on my 845 monoblocks. Without a doubt, the same thing happened, just like the first post claimed.

A few years later I became a dealer and a friend of mine was advocating for Acacia wood plinths underneath his speakers. I had a hard time believing it at the time, but I decided to go to Bed Bath and Beyond and picked two of them up. I had my speakers (Rosso Fiorentino Elba) sitting on granite slabs at the time. I moved the speakers and put the Acacia on top of the granite. Believe it or not, the Acacia warmed up the sound of the speakers compared to the hard sound of granite. A friend came over shortly after who told me a dozen times that he wouldn't hear the difference. After doing the switch, he said it was completely obvious.

I tried the Acacia underneath several components after that and found that it changed the sound on my untouched gear, while it had little, if any effect on my dynamatted components. Why is this important?

Simply put, resonances feed back into your music stream and alter the tone of your music. If something is hard, its resonance will be higher, and your sound will get harder. If something is soft...
 

Talley

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The mapleshades shelves really work well. I'm planning on a mapleshade rack and doing maple blocks under my mains/center

20150615_175107.jpg
 

billrobbo

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If this was done sighted, then nothing much can be taken away from it. "I heard it with my own eyes" oops. I mean "ears" :p. These scientifically sketchy devices are typically debunked with blind testing. Which is why they're never tested blind during demos.

Sighted bias cannot be discounted, particularly when the scientific basis for the change is highly suspect.

Just my opinion. :greengrin:
I totally agree. Unless you have strict double blind testing you can not rule out perception bias. Full stop.
 

Mark C Flick

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No additional isolation for me, just what the equipment came with. Only exception is my speakers though not because I buy into it, it's just to protect the floor. I'm not totally against it, for example, I do believe a turntable benefits from isolation but that's about it for me. This is purely based on belief, I have done no testing or experimentation.
 

Todd Anderson

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@Mark C Flick I'd be curious to sit with you during a demo and see if you could hear differences. And I agree with @billrobbo, there can certainly be perception bias.

Several years ago, I sat through an IsoAcoustics demo with my eyes closed and heard very clear differences (in fact, post CES I have some of their GAIA stands up for review).

Interesting topic, no doubt.
 
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