Blind Power Cord Test & results

All my power cords are blind, I don't need to test them to verify that.

I'd suggest this approach.

Amongst the audiophile community, there is a very significant statistical majority that there are audible differences in cables. These are people who have done all kinds of listening tests in their home environments, and many would have preferred to not spend any unnecessary money.

These differences are statistically significant enough to comprise a valid observed phenomenon, over a disparate group of individuals.

Now, the scientific response should be that since existing electrical testing methodology has only shown minor differences,and that A/B/X testing has not determined anything sufficient, that there must be some other testing methodology found to either support or refute this widespread observation.

Case in point: When optical communications networks are used, fiber-optic cables carry the signals. Electricity is applied to one driver, and comes out the other end's receiver as electricity(of course opto-couplers are used in this case, but bear me out). If I took that fiber-optic cable and tested it for electrical characteristics, it would seem that it wouldn't even carry any electricity, and it won't. But that doesn't mean that signals are not carried on it. You have to design your testing protocol to measure what you are trying to determine. When we add in the opto-couplers and know(ahead of time) that we are transmitting light signals with couplers on both ends, then we can measure the performance adequately. Similarly, we don't really know for sure(and this whole thread bears this out) what we are trying to measure. All we know is that the existing measuring techniques are apparently not adequate to account for a statistically significant and widespread observation.

So, one way to deal with it, is to just "dismiss" it as folly, or imagination. The other way is to figure out why the tests are inadequate, and determine new tests that actually can make some headway to finding out how to measure what is so commonly observed. The first step in this is to try to determine what the cables are doing that is not in our testing.

If every scientist dismissed everything that could not be readily measured at the time, we wouldn't know anything at all. Measurements are made to quantify observed phenomenon. Anything that is a statistically significant occurrence, justifies further investigation to find tests that can quantify it, whether they be electrical tests or acoustic tests, or whatever.

Something is going on here with these cables, and it would behoove us to find out what it is, and why it is.

Something is going on here with these cables, and it would behoove us to find out what it is, and why it is.

This is an excellent example of assuming one's conclusion. If every scientist did this, we wouldn't know anything at all.

Scientists *do* know why people hear differences between cables. Some others, it seems, would rather not know.

Twl...No doubt that "something is going on", but the question is: should the investigator be a scientist or a psychologist. Probably both, IMHO.

Some people believe in psychic phenomena, and many tests have been devised to try and prove, by statistical means that psychic phenomena exist. No one is convinced, except those who believed before the tests. However, IF someone were to discover, not that it exists, but HOW it works, some kind of electromagnetic radiation between brains, then it's existence would not be in question, even by people who lack the ability.

So, people who want to convince me that exotic power cords affect audio equipment, need to come up with some rational explanation as to how this might happen. So far the various "scientific" explanations that I have heard fall short of credibility.

QUOTESo, people who want to convince me that exotic power cords affect audio equipment, need to come up with some rational explanation as to how this might happenQUOTE

Right on! I mean, heaven forbid we should have to listen ourselves and make our own decisions. That's why scientists get the big bucks, right? :^

Some people believe in psychic phenomena...

And some people are Psychic phenomena!!!

Joke aside, Eldart, don't confuse metaphysical with psychic...

If you can't hear a difference, what difference would any "scientific" test make to your listening experience? For those of us who can hear a difference--where we have put ourselves to the "test" of reliably distinguishing between some cords in our systems--what is there to prove? I don't really understand what explains the differences I have heard between some cords, interconnects and speaker cables. Nor do I care. Nor do I want to convince anyone else, beyond recommending that they listen for themselves. No one is threatening to deny cord nonbelievers their rights and liberties. As for the psychic phenomena comparison: if someone could reliably tell me what numbers I had written down, out of her view, I wouldn't doubt she is "psychic." While scientists would no doubt like an explanation of this phenomenon, the absence of a scientific explanation would bear not at all on the reality of the phenomenon. So I am not sure why the science-types continue to insist on proof from those of us who are mere listeners--unless they are actually directing their skepticism only to those science-types who also claim to be able hear differences between some cords.

Lmack...You missed the point about the psychic. No doubt you would believe her, although the trick is probably done by a mirror or something like that. The point is that if the mechanism for psychic power were discovered, then it's existance would be accepted by sceptics. Don't argue that it exists...tell me how it works. You may not care how it works, but that's your ticket to credibility.

This is an exercise in understanding human nature, not audio.

Bye.

QUOTEDon't argue that it exists...tell me how it works.QUOTE

Exactly...it doesn't count unless you can explain it! Kind of like why we're all here. We aren't, really, unless you can explain it. Again, that's why scientists get the big bucks. Until they explain it, I won't believe I'm really here...plain and simple. :^

You know, scientists say that bumblebees can't fly, and that from a technical perspective it is impossible. Yet, bumblebees fly all the time. Perhaps we need to do some A/B/X testing to see if we actually are seeing bumblebees fly, or if they are actually not flying, and we are imagining it.

For a hundred years, thousands of scientists and mathematicians have tried to explain how bumblebees fly, and still can't explain it, even to this very day, and this very moment.

I suppose that some here think that we are imagining these black and yellow furry insects flitting about our yards, blissfully ignorant of the "proven fact" that they cannot actually be there.

I'm sure that there must be some psychological explanation for all of us seeing these phantom apparitions that could not possibly be doing what we think they are doing.

You know, it's amazing how widespread these sightings of bumblebees in flight are. One would never think that it could possibly be so pervasive in a society of thinking people who should know better.

Bumblebees have been measured, tested, observed, computer modeled, mathematically analyzed, real-life modeled, and it has been determined that they cannot fly. Boy, I feel alot better, now that I know that.

It is annoying to me how little audiophiles/public understand science - not in specific examples like bees and PCs per se, but in the way scientists are supposedly rigid, archaic formulists reminiscent of Pink Floyd’s The Wall. In my experience, scientists go to the fringe of knowledge and theory with a lot of grace, unlike the people who try playing the role.

I personally believe cables do make a difference and knowledge of the make-and-model has an influence of perception through expectation. I hope most phile’s, in the silent majority, are in the same boat. And like I stated ABX and blind between-subject testing are perfectly viable in eliminating expectation. An experiment’s procedure may be flawed and the conclusions may not fit the data, but I have yet to read or hear any logical reason why these tests are inherently flawed. One may not like the results, but ya' need more than that to discount the test.

Bumblebee physics myth:

http://www.howstuffworks.com/news-item223.htm

I find many of the posts in this thread disturbing. I hope the inability to follow a logical line of reasoning is an anomaly unrepresentative of our population generally. One poster even tosses around statistical significance as though it had meaning outside of sampling, distribution, variance, and inference. But that's just misuse of jargon. I'm really concerned about the apparent inability to reason logically from premises to conclusion. Is this thread about auditory perception or religion? I get the impression it's about religion: You are either a believer (that there are audible differences that can be heard by the discerning few) or not.

Although I was director of a high-tech research center, my original training was in psycoacoustics, particularly binaural auditory processing. I've been addicted to HiFi since before stereo. I admit my speakers are bi-wired, and I have no idea if it makes a bit of audible difference, but I like them that way.

db

Despite my reaction to his posts, I agree with Twl more than I disagree. The parameters such as system and room need to be addressed and while ABX is good tool, it is not worth much on many levels in audio, especially in private circumstances. Also, in future threads, subjective discussions should not be interrupted by contrarian physical explanations and vice-versa. There is no point to it.

I never believed in sonic differences of power cords, and I laughed at those who did. Then, when I finally broke down and decided to try a high-end cord, I couldn't believe the improvement. Even a skeptic friend of mine was immediately converted after he heard my new power cord.

I have since used many power cords better than this first upgraded cord. I have no interest in reading 'tests' that discredit power cord differences, as I know, beyond a shadow of a doubt, that they can make as much of a sonic difference as different interconnects make. Yes, I'd like to know why and how they do this, but until and if the scientific reasons manifest themselves, I'm satisfied to know that they do.

I can listen to one power cord on a component using 2 or 3 music selections, and then switch to another cord and tell you what the sonic differences are. I can also have one cord in my system for a week, then change to another cord and be able to hear that cord's signature clearly. I have put stock cords back in only to be horrified by how inferior they sound.

I don't like spending money on power cords, and wish they all sounded the same. Problem is: they don't.

In a very interesting post above, Donbellphd notes:

Is this thread about auditory perception or religion? I get the impression it's about religion... (...)

Somewhere in-between, I'd say, and closer to religion: music is an emotional experience and the equip attached to its reproduction seems to borrow from that emotionality... hence a partial (at least) explanation of

...the inability to follow a logical line of reasoning

. As such it could be termed

an anomaly (REPRESENTATIVE) of our population

. There must be similar anomalies representative of other populations -- music maybe (as in, which is the best performance of Mahler2 and why).
Other than that, I also agree that some of the things tossed around make little sense including, sometimes, blurb tossed around by manufacturers of reproduction equip.
At the end of the day, most of us don't know much about circuit design and loudspeaker modelling -- nor should we. Add to that the bickering between engineers who DO know about these subjects which seems to add to the population's confusion...
Cheers

Also, in future threads, subjective discussions should not be interrupted by contrarian physical explanations and vice-versa.

This is a misconception. These threads get onto the question of "what's real/what's in our heads" because people begin offering totally nonsensical explanations for how cables/tweaks/PCs/etc. work, and others pointed out their errors. Now, maybe you think Audiogon is served by a rule that says, only *incorrect* technical explanations may be posted. But when I say something wrong (and I do), I want to be set right, because that's how we all learn.

There is a logical train of reasoning going on here. We hear a repeatable thing, and look for reasons why it is a repeatable thing. But, just because we have not found many reasons why yet, is no cause to dismiss it.

My link to the Bumblebee story
http://www.pass.maths.org.uk/issue17/news/bumble/index-gifd.html

This is not "religion" or anything like it. It is simply another case where the scientists have not produced much proof to explain a valid repeatable observation. But they have produced some, and even that small bit of proof(differences in resistance, impedance, capacitance, dielectric) shows that there can be some differences that will be audible.

Is this must be the new "scientific" game? "If an easy answer isn't apparent, it must be psychological."?

Just like the bumblebee story shows, scientists don't know everything, never knew everything, and are not likely to ever know everything. Evidently, there are some who think they do.

As I posted earlier, member Aball has written on another thread about a French and German scientific consortium who is studying this very subject, and have already found some things that can be measured, and can further explain why we hear differences. These are hardware measurements, not psycho-acoustic measurements. They have found some kind of "micro-corona" effects around wire which is measurable, and they have produced some kind of measuring device to quantify it. I don't know much about it, but at least someone is doing something about it.

I don't much care about it myself, since I can easily hear the things needed for me to make an informed decision. However, for some who can't trust their ears, and have to lean on numbers for their audio purchasing, this may be helpful.

Psychics don't have to guess numbers to be psychics. That would just be a game--and there are more important things to be done helping people.

You guys need to see a good clarvoyant psychic to find out what can he/she tell you...whether reading the cards, shells, tobacco smoke--you name it.

Whith psychic power and primal intensity,

***

Dragon1952...You also, and others still miss the point about the ROLE of a scientific explanation of physical effects. I will say it another way.

Not everything requires an exact explanation. (Don't misquote me!). I believe in Gravity, even though its explanation is imperfect.

If I believe, based on listening and science, that some audio tweek doesn't, and cannot possibly, work, a hundred people saying it does won't have much luck convincing me. But if one guy can show me HOW it functions then I cannot deny that it works.

Pabelson I love discussions/arguments about technical discussions. I also believe some number of technical explanations marketed by companies are BS and deserve scrutiny. What I was thinking of were technical discussions where a subjective counterpoint is introduced stating that everyone is being cheap and also the the lame "its all in your head" one-liners when posters are discussing their listening experiences with tweaks, cables, etc.

Eldartford....I'm glad you caught the sarcasm anyway. It's sometimes hard to convey without smiley faces. The one that rolls his eyes works pretty well. :^

QUOTEIf I believe, based on listening and science, that some audio tweek doesn't, and cannot possibly, work, a hundred people saying it does won't have much luck convincing me.QUOTE

LISTENING + SCIENCE is probably a good thing. It's the ones that rely strictly on science (or a/b comparisons) that bother me. BTW, a/b comparisons is NOT "listening".

"Pabelson I love discussions/arguments about technical discussions."

I think I may be retarded.

This all reminds me of the time I attended a Stereophile-sponsered exhibition/convention (which I believe they hold with some regularity). I was a salesperson at a high-end audio store at the time. At the show, they had one of those "can you tell the difference" events (repeated at least twice, as I recall).
In this case, the comparison was between a top of the line Adcom solid-state amplifier and another amp of a much higher price and, presumptively, of better quality. The test consisted of the playing of ten sets of two different auditions of the amps. Each set of ten consisted of our listening "blind" to two auditions and, then, writing down whether we thought that the particular audition was one of the two different amplifiers, or whether it had, in fact, been of the same amplifier played twice. We were told to write down "same", or "different" for each one of the ten sets of auditions. We were told to not try to identify which specific amplifier had played at each separate audition. Presumably, that would have confused us, utterly, or even, perchance, driven some of us mad.
It was a large room, of about two hundred people. I had the good fortune to be seated in the rear corner of the room. I had decided, counter to our instructions, that it would be more challenging, even, perhaps, subversive, to, indeed, write down the name of the specific amplifier that I believed played each time.
I made all my decisions within the first two seconds of each audition. The person seated next to me actually stood up and complained that my responding so quickly was distracting and confusing him. This pleased me because, as I am a philosopher, I'm in the business of distracting and confusing people.
To make a long story even longer, I was right nineteen of twenty times. (Naturally, I blamed my one mistake on the fellow seated next to me.)
How was I able to do this? Simple. I didn't try to hear any differences, at all. Instead, I relaxed into a near meditative state and concentrated on "listening" to how my body felt. I, then, immediately responded according to how my "mood" had changed the instant the music began to play--and, luckily, one amp made me feel better than the other. I kept my conscious mind nearly empty (something that I can do quite easily). Most importantly, I never left myself enough time to second-guess myself.
There is an instructive and brief Buddhist tale about a monkey who is so desperately thirsty that he sat by a stream and grabbed and grabbed at the flowing water such that he could never get a drink. But, as soon as he released his grip, the water flowed immediately and effortlessly into his cupped hands. Thus, his thirst was sated.
Don't grab at the river of music as it rushes by. Dip your hands in, let it pass, and you, too, can effortlessly drink from it, as you're caressed by its ebbs and flows.

Hmmmm....you think that would work for nookie too or should I stick to my lucky shirt?

The first time I sat down to compare an "audiophile" power cord to a generic one, I was 100% sure I would find no difference. The idea seemed absurd to me. But listening to certain cords, such as those from Shunyata, quickly demolished that notion. Furthermore, I heard the same things that I subsequently read about in reviews.

This is to me more relevant type of blind testing than sitting through short selections. I was blind to the possibility of differences, and I was blind to the types of differences that others were hearing on these same cables.

I don't kwow whether the cord that was used for testing in this article has a substantial sonic signature or not. I am certain that I could prepare a test between two cords where listeners would hear little or no difference, because there isn't any apparent sonic difference between the cords. (I'm referring to sonic differences, not price differences ; - )

Art

I've tried various pc in the past and most do change the sound one way or another. A/B doesn't work for me, it usually requires atleast 3-4 days for the differences to by fully noticeable. I have just in the past month went through three different pcs on my source. The first 3-4 days they all sounded very similar, with the only slight noticeable difference in the bass area. After 4 days or so, the differences became more apparent and each takes my system to a slightly different direction.
I don't know the technical workings of this (feel free to jump in Sean,) but I think it has something to do with the pc itself being electrically charged up. From my experience and imho, the neuances of each cord would only reveal themselves after this length. Any A/B comparisons that I have done prior to said time often yield inconclusive results. If I had only done A/B comparisons, I may have drawn the conclusion that they make no differences.

I don't need someone elses review, I have done my own. I replaced the AC cords on my DVD player and front projector at the same time with VHAudio cryo'd AC cords and the video was dramatically improved, nothing subtle about it. I was not using any power conditioners at the time. This was on a well calibrated system I was naurally familiar with and it was immediately apparent. Perhaps video is easier to perceive than audio.

Welcone to Statistics 101, and so snickering, please.
A not all that close reading of the article will lead anyone familiar with experimental design to conclude that the results are without meaning. I'm sorry I didn't see this thread sooner so my comments could be more current. The sections in quotes were cut and pasted from the article.

1. Reading the article from “Secrets of Home Theater and High Fidelity,” it is apparent that the procedure has many, many steps that might influence the results and that the two groups had different procedures used. The non-comparability of the groups and multiple steps mean that the overall procedure may be flawed. Is there “proof?” No, but there is equally any lack of evidence that this is a valid procedure. Stop, start; un plug, replug;(on multiple components, no less), power down, power up; warm-up; musical selection length determined, how? Half of the participants attended a “training session” the month before. The second trial had musical selections that were longer than the first. Group one (no snickering here, please) had the felt down for the training and felt up for the listening. Group two were felt up both ways. ( I said, “NO SNICKERING!”) Group one ate after the test and greeted Group two. Group two ate before the test with Group one. Lots of experimental manipulation, all of which was quite apparent to the participants. What might this have done? Still, the two groups were different from one another and were different interanlly by virtue of the pre-trainning. At a minimum, the data from the two should not have been aggregated.

“Participants were 80% correct in their responses to the selection from the Berlioz Requiem. Manny calls this “very close to the threshold between chance and perception. None of the other selections produced responses higher than 60%. This phenomenon correlates with John Atkinson’s experience that his participants fared best on massed choral music. If any of us were mad enough to conduct another blind test of this nature, I would choose audiophile recordings of massed choral music for at least 50% of the musical selections. It would be interesting to discover if it would make a difference.”

2. The procedure apparently produced at least one condition that had uniformly positive results, but Manny says it doesn’t matter. How did Manny reach this conclusion?

“In post-test discussion, several of us noted that we had great difficulty remembering what A had sounded like by the time we got through with X. Several participants said that the way they dealt with this phenomenon was by ignoring A entirely and simply comparing B to X without giving thought to A.”

3. Procedures may well have skewed the results.

“In many cases, statistically significant differences could be discerned by participants. In others, no differences could be discerned.”

4. He does not make it clear how he determined this. Even earlier in the review, he noted:

“...that the very procedure of a blind listening test can conceal small but real subjective differences....”

5. Hmmm.....

"But, no, you have to take all the data together. You can't just pick out the numbers that suit your hypothesis. This would be statistically invalid. Same thing with just looking at one music selection."

6. But, if the procedures have many elements that compromise the overall validity, this conclusion is unsubstantiated.

The fact there was some evidence of statistically significant differences some of the time suggests that something may have been going on. Lumping all of the data together is not necessarily a good statistical procedure, particularly with so may manipulations going on and the differences between the two groups and individual participants by having attended some pre-training. With any group, it could be that there is one individual who can detect differences, or one type of music that makes this more detectable. No one is really sure of what to make of statistical outliers (those many standard deviations from the mean), but citing group statistics does not address the issue, particularly with small groups.

"But, we can't do that and claim good science."

7. Calling it science does not make it science.
These procedures may or may not be flawed. What is clear though, is that there is very little statistical power in such procedures -- two small groups with a large number of experimental conditions.

My conclusion is that nothing can be learned from this test as structured. Using statistical procedures to analyze poorly run experiments cannot redeem the experiments. Lots of experiments designed by far more accomplished folks are found to be flawed. This would never be published by anything other than an on-line audiophile publication.

Buy a better power cord and decide for yourself. Get it from a source that allows a trial period.

Rouvin

What a damn shame they didn't consult you before the test. How could they be so stupid? Thanks for setting us all straight.

Drubin,

Perhaps I was a bit too jocular in that post. If this obscured my point, sorry about that.

My point was that good experimental designs are very hard to accomplish, and this experiment had so many difficulties, I can’t see how it could be valid as a tool to help decide about power cords. Perhaps, most could see this, but I read this article after seeing it cited several times by others as a source of information to try and decide if after-market PC’s were worth it. Good experimental design is no minor issue. Academic and scientific careers can be made and destroyed in this area. Carefully applied and properly used statistics can’t improve an experimental design with major flaws.

I have yet to read any sort of blind test in audio that had an experimental design that appeared convincing to me, but I read that stuff only when I'm looking for something specific. A frequently cited difficulty, on Audiogon and elsewhere, is that blind testing itself may introduce some inherent bias, but the technorati surely disagree. Many other factors that are more complicated could also be mentioned, but I won’t.

Lots of folks would like to know the answer to questions about upgrading/changing things like PC’s definitively, and that is why such tests have been devised. It just seems like we have a long way to before we get there, if ever.