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Observations of a controlled Cable Test

99K views 383 replies 63 participants last post by  JapanDave 
#1 ·
[continued from http://www.avsforum.com/avs-vb/showt...18365&page=59]


Morning!


I got back a little late last night and didn't do a writeup then, I figure Mike will post his impressions at some point too.


First of all, kudos to Mike for being the always-gracious host, and also for his fairness and open mindedness for this trial. It is fair to recognize that he only had something to lose, and nothing really to be gained except perhaps an objective vindication of his position.


And to cut to the chase, Mike could not identify the Monster from the Opus MM with any accuracy (nor the reverse, which also would have been a positive result if he had been consistently wrong) using our testing methodology. We stopped the test a little less than halfway through, I think we got through 8 A/Bs before we gave up.


There were 4 of us present at the test. Mike had performed sighted listening tests on his own, and before I arrived he performed sighted listening tests while wearing a blindfold to acclimate himself to the testing method. His blindfold was a pair of duct-taped safety glasses. He could not see anything except a tiny bit directly below him. Theoretically, he could have strained his neck and been able to see the floor by the speakers where the wire was, but this was not allowed. After all, cheating would only serve to cheat himself. While switching wires, Mike wore earmuffs to minimize any possibility of identifying wires by the noises of switching the wires.


The plan was to do twenty A/B trials, which were chosen by flipping a coin. This was done before I arrived. After I arrived, we decided to check the level-match between wires. We did not have a method to level-match the wire if they were non-matched, however we also felt that the wire should match. Because the Opus uses some kind of network box, it conceivably would be possible that the signal were attenuated or otherwise altered and change the level, making it possible to identify the wire this way, rather than by sound 'quality' per se. The levels matched with a sine wave tone within 1/100th of a volt, the difference between the two sides was several hundredths of a volt with both wires. The difference between the L and R channels was greater than the possible difference between wires, which anyway was insignificant. We decided to check this because while we had no way of matching levels precisely, if there were a level difference we would have added a step to our methodology by turning down the volume all the way and then allowing mike to adjust the volume up, which would eliminate the ability to judge any difference in volume. We didn't need to do this, so Mike could listen without having to change the volume all the time, however he was free to change volume if he wanted.


There was, being generous, about one minute of a wait between changing cables. This was the case for both the sighted preparatory tests, and the blind tests. His amp basically goes straight through, so even with it turned off, it is feeding the speakers for a while. We would wait a little bit after turning off the amp before disconnecting the speaker wire and switching wire. We took care to be quiet while putting the wire down so as not to make any noise which could distinguish the wire. We changed the wire each and every time, regardless of whether switching to the other cable. At each time Mike would wear the earmuffs, even if he was going back to a known test, again to eliminate any possibility of identifying the wire by the noise of changing the wires.


We did at one point stop and go play pool for a few minutes and then come back to the test, doing a sighted (though still blindfolded) test to re-familiarize Mike with the cables.


So our results with Mike as our listener were clear: for this particular methodology, Mike could not accurately identify a difference in the cables. Again, a backwards result of Mike wrongly identifying the cables reliably also would have been a positive result.


I went into this with a fairly open mind. I did not have a previous opinion on the difference in speaker wire. However, I am fairly objective, and I did have two main expectations. First was that speaker wire, even if it did have an audible difference, would be very insignificant in the scope of the overall system. If there was going to be a difference, I was expecting it to be extremly subtle, and small. In other words, being objective about speaker wire tells me that it is fairly straightforward if you have sufficient gauge that the wire should basically get everything to the speaker with a precision that exceeds our hearing ability. Second, if there was going to be a difference, the suggested possibility of the network box in the Opus rolling off the highs may have caused an expectation of slightly less brightness/detail.


I personally went through the first few trials sighted, helping to change the wires. Going into the test I had no set opinion beside the expectations I just described. And while I am quite objective, objectivism also tells me things about vinyl which are quickly disproven in Mike's system. So I am open to these kinds of subjective things as well. As I went through 3 sighted trials, I began to form an opinion which basically told me that there WAS a difference in cables. Subtle, but I can say with confidence that it was present. I thought the Monster cable was a bit harsher, with a little bit less separation between instruments. This may have been a bias from my expectation that the Opus network box could have been attenuating the high frequencies, but I swore it was there. It is interesting to me that while I formed this opinion not having heard Mike or anyone else describe what they thought the difference was, after we stopped the whole test, Mike described what he previously thought the sighted difference sounded like (what he was listening for in the test) was practically identical to what I thought I was hearing sighted.


Then, for my own curiousity, I did the remaining 5 A/Bs before we stopped the test at 8 A/Bs blinded. I didn't wear ear muffs, and I just closed my eyes. I could have cheated if I wanted, but I did not (I guess you just have to take my word). I also, to check the rigor of our methdology, tried to actively listen to the cables being switched and see if I could identify either, to see if there was a way of identifying which was which that might have influenced mike even with earmuffs. There was no way to identify wire this way. I had looked at our test sheet, but I made no effort to try to memorize the sequence or have any idea what I would be listening to. In my 5 trials, I was certain on 3, and relatively uncertain on 2. I only matched 3 our ot 5, which is basically just blind luck, and I only got 2 of the 3 I was certain about correct. In other words, as a second, just self-interested and self-blinded tester, I could not with any reliability identify a difference in the cables.


The results for Mike and also the non rigorous one for myself certainly undid the opinion I was forming during my sighted listening. To characterize the position I've come to, I think it's fair to say that the objectivist arguments have a great deal of merit. It is fair to say that the onus is on subjectivists to discern speaker cable differences reliably. However it is ALSO fair to say that it is very difficult to prove a negative, especially for people with a subjectivist bent. Objectivists must also be honest about what our test results tell us: that with this methodology, and with this methodology ONLY, we could not reliably discern any differences in the cables. This does not prove that there are no differences with the cable, only that there were no differences discerned with this method.


In my personaly opinion, doing a long line of tests like this is generally unpleasant to do, you get tired of listening to the same stuff over and over, and after a little while it all starts to sound the same. Also, Mike only went back to a known A/B once during the test. I still would be interested in a similar test but spread out in time, doing maybe only one or two A/Bs at a time. This keeps fatigue down, and things don't all start to sound the same (again, just for the sake of argument assuming that there is an audible difference).


However, this test does tell us that even assuming for the sake of argument that there is a difference, that such a difference is extremly small, since it could not be percieved reliably with this method. After we finished the test, for curiosity we cut the ends of 16 gauge extension cords, and connected them to the system. We did this sighted. And the system sounded absolutely fantastic. The result I came away with through the whole experience is that people should generally not fret about speaker wire. Using a speaker wire of sufficient gauge for the task gets the job done. Even the unreliable sighted 'impressions' I had of the difference between Monster an Opus, which can not in any way be fairly attributable to actual difference, was extremely subtle. And the 16 gauge sounded basically exactly the same too.


After the test Mike was very gracious, and very fair and honest in accepting the result. I think he is probably curious to do some more testing in a different A/B format, perhaps along the lines I suggested. Or perhaps an ABX type test. It was curious that after the test, he characterized his certainty that during the test, it seemed fairly clear which was which. However, he was not identifying the cables with any consistency (rightly or wrongly) during the test. He did stop though and we left to go play pool to get away from the testing, so it seemed to me as an observer anyway that he was beginning to have difficulty, at least from his perspective, in identifying which was which. However, he was before that time not being at all consistent.


So I think that's basically everyting that either side would want to know. And I'm sure there's plenty of ammunition for both. I can say now that I am of the opinion that speaker wire basically makes no significant difference in sound quality, given sufficient gauge. Even the 16gauge extension cord was fantastic. I am still open to the possibility of audible differences with speaker cable, however such differences must be quite small and very subtle.


After the test, Mike played a handful of records, and I played some CDs as well. And what I came away with perhaps more than that is that Mike has probably the best overall system I've ever heard especially for BIG music. Big orchestral and rock sounded simply unbelievable. Santana, the Gates of Kiev, and Zeppelin among others on vinyl were just absolutely incredible. A completely new experience. I was trying to be extremely picky, and while I've heard a system here and there do small things differently in ways that in my opinion were slightly better, stepping back and considering the whole picture: it's simply an absolutely incredible system. The best I've ever heard big complex music.


So thanks again to Mike for being open and fair through the whole test and setting it all up and putting in the time and effort even though he really had nothing to gain. And for the pizza!



So flame on. If I were Mike, I frankly wouldn't care that much anyway, cable difference or not, it's one hell of a music system.
 
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#105 ·

Quote:
Originally Posted by Bob Lee (QSC) /forum/post/12268558


They are no more insensitive to subtle sonic differences than sighted tests are. They are, however, amazingly insensitive to imagined sonic differences, which is why they are far more valuable than sighted tests.

Amen, Bob!


What's more, the performance of DBT's in threshold tests gets down to within -->||
 
#107 ·
Mr. Risch may be right, about different brain activity occuring in 'sighted' vs 'blind', but it doesn't have the implications he thinks it does.


This is a quote from the wiki article on placebo effects. The date links to the actual article by McClure et al published in Neuron, a highly respected scientific journal of neurobiology.

Quote:
A complex fMRI-centred study by McClure, et al. ( 2004 ) on the brain responses of subjects who had previously expressed a preference for one or other of the similar soft drinks Pepsi and Coca-Cola, demonstrated that "brand information", which "significantly influences subjects’ expressed preferences", is processed in an entirely different brain area from the area activated in blind taste tests (when their "preferences are determined solely from sensory information").[33] This supports the claim that there are unconscious brain processes that activate the "placebo response".

This certainly doesn't imply that sighted judgement is MORE ACCURATE than judgement from 'pure' sensory input (blind). It implies that 'sighted' input activates a different brain area than 'taste data' input, and the judgment is affected by this -- it's virtually DECOUPLED from actual taste input. That leads to things like inaccurate identification of the drink. People who have a stated preference for Coke, will not be able to tell if it's Coke when blinded...and they will state a preference for 'Coke' even when it's really Pepsi with a Coke label on it. This 'cultural' bias has a brain activity correlate.


Here's the actual abstract of the Neuron paper:

Quote:
Coca-Cola® (Coke®) and Pepsi® are nearly identical in chemical composition, yet humans routinely display strong subjective preferences for one or the other. This simple observation raises the important question of how cultural messages combine with content to shape our perceptions; even to the point of modifying behavioral preferences for a primary reward like a sugared drink. We delivered Coke and Pepsi to human subjects in behavioral taste tests and also in passive experiments carried out during functional magnetic resonance imaging (fMRI). Two conditions were examined: (1) anonymous delivery of Coke and Pepsi and (2) brand-cued delivery of Coke and Pepsi. For the anonymous task, we report a consistent neural response in the ventromedial prefrontal cortex that correlated with subjects' behavioral preferences for these beverages. In the brand-cued experiment, brand knowledge for one of the drinks had a dramatic influence on expressed behavioral preferences and on the measured brain responses.
 
#109 ·

Quote:
Originally Posted by penngray /forum/post/12271791


lmao, honestly, work has been really boring in the past couple of months so I have to come on here to get excited and alteast create a good amount of stress......I would be falling asleep otherwise

Now, if the listener received an electrical shock everytime he picked the wrong cable . . . that would be stressful.
 
#110 ·

Quote:
Originally Posted by Swampfox /forum/post/12272100


Now, if the listener received an electrical shock everytime he picked the wrong cable . . . that would be stressful.

Are you implying that electric shocks are not standard protocol for blind testing?!!


(Rich goes back to drawing board, realization of why people refuse to take part in any more of his tests begins to dawn...)
 
#112 ·
I think you can find 'clubs' where people are into that sort of thing, Richard.
 
#113 ·

Quote:
Originally Posted by FrantzM /forum/post/12265228


Surprising ? No.. Remarkable? Certainly.. From the start MikeL has been a gentlemen even in he face of ad hominem posts...

Frantz,


I believe it is surprising insofar as the normal reaction when a persons core beliefs are challenged is to make excuses and cry foul. In fact, when it comes to people failing cable tests it occurs nearly 100% of the time. So for me yes, Mike's reaction is surprising, and that is a compliment
.
 
#114 ·
MikeL-it seems that it wasn't too long ago that you were going to leave this forum for good and I have been happy to see that you have not only stayed but have become active again. Know that if you keep on this path of cable testing and show that you can tell the difference in cables you will change me into a believer. But until then
....


Mr Hirsh-your post is a fabulous diatribe in denial. Your disciples should be proud....
 
#115 ·
I will agree with the stress thing.


Almost any kind of testing is stressful. not because i might fail or pass, but because i have to pay attention to things that are normally not part of my focus.


As an example, i just had to do an evaluation of Telepresence solutions. when conducting the conference, my brain was going at double speed analyzing the latency, the audio, the video, trying to then break apart what is related to the codec's and what is related to the gear... etc, etc, etc. So while others came out of the demo saying how awesome it was, i had 100 times more input to process and was wiped after a one hour meeting.


So in any case where a test is happening and you are being serious about it, you will find it stressful due to the fact that you are recording far more stimulus than if you were just sitting back getting comfortably numb.
 
#116 ·
I have not read every post so I don't know what has or has not been said about the stress thing but "stress" is another red herring. Stress might cause some people to fail in certain endeavors, I'm sure some people fail the bar test because of stress, yet amazingly, many people sill manage to pass and become attorney's. Since audiophiles ALWAYS fail the cable comparison test, I think we can logically conclude that stress is not the primary causative factor.
 
#118 ·

Quote:
Originally Posted by Dizzman /forum/post/12276211


I will agree with the stress thing.


Almost any kind of testing is stressful. not because i might fail or pass, but because i have to pay attention to things that are normally not part of my focus.


As an example, i just had to do an evaluation of Telepresence solutions. when conducting the conference, my brain was going at double speed analyzing the latency, the audio, the video, trying to then break apart what is related to the codec's and what is related to the gear... etc, etc, etc. So while others came out of the demo saying how awesome it was, i had 100 times more input to process and was wiped after a one hour meeting.


So in any case where a test is happening and you are being serious about it, you will find it stressful due to the fact that you are recording far more stimulus than if you were just sitting back getting comfortably numb.

OK Dizz, but how do you think your stress level would've been had that been the 10th time you'd seen it?
 
#119 ·

Quote:
Originally Posted by QQQ /forum/post/12276335


I have not read every post so I don't know what has or has not been said about the stress thing but "stress" is another red herring. Stress might cause some people to fail in certain endeavors, I'm sure some people fail the bar test because of stress, yet amazingly, many people sill manage to pass and become attorney's. Since audiophiles ALWAYS fail the cable comparison test, I think we can logically conclude that stress is not the primary causative factor.


Correct!
 
#121 ·
If the test protocol is wearing, just do it exactly the same way the person determined they could hear a difference in the first place, i.e. casual switching, except that someone else does the changeouts and the listener doesn't know which cable it is.


For a lazy guy like me, that would be *less* stressful.


Unless of course I cared which one sounded better.
 
#122 ·

Quote:
Originally Posted by Dizzman /forum/post/12276211


I will agree with the stress thing.


Almost any kind of testing is stressful. not because i might fail or pass, but because i have to pay attention to things that are normally not part of my focus.

But how would that be different in a 'sighted' comparison -- which is what

'audiophiles' tend to do? Any audio comparison of two things is not quite like 'normal listening'...where you're not comparing anything. Yet every audio component review is at heart a comparison. Are all those guys (it's almost always guys) in Stereophile and Absolute Sound and the mainstream mags stressing themselves out? Doesn't sound like it from what they write.


Mike L. seemed to have no 'stress' problems when comparing cables on his own. He heard those 'obvious' difference just fine.
 
#124 ·
Of course testing can be and usually is stressful. I can not fathom how anyone who's ever actually done any testing could not see that. Are you familiar with "testing anxiety?" That's some "elementary" stuff, pun intended, in the field of psychometrics. Part of designing any test is to try to make sure you are measuring what you are actually intend to measure. You can be measuring something but that something can be "test anxiety" and not what you think you are measuring. This just a small educational study which has results that are typical http://www.eric.ed.gov/ERICWebPortal...accno=EJ616811 . I always suggest that my younger relatives take the ACT and SAT several times, for example. The truth is that they are not going to learn a lot between the different testing dates. They may learn some things which will improve their score. As someone in the field of psychology I know that the more they take the test, the less anxiety they will have and that is correlated with the score they will recieve. For example, if say they need a minimum score to gain admittance, once that is met, test anxiety should go way down. Then when they take the test, with nothing to lose, their scores usually go up. The anxiety factor has been diminished. This is also why it can be difficult to replicate results on test of single subject. If you keep giving the same subject, the same test, what you may be measuing may not an "improvement" on the testing subject but rather a reduction of testing anxiety. To have a test that you can replicate, you use the same testing condition with subjects with the same level of experience under the same testing condiions. Usually, NO, experience is preferable.
 
#125 ·

Quote:
Originally Posted by tbrunet /forum/post/12282004


Remember the difference was not subtle.

Today's word is "indictment".


Let's keep in mind that Mike has admitted that he couldn't tell the difference, regardless of what he said in the past. Even the most egregious sinners are allowed to recant in search of forgiveness
 
#127 ·

Quote:
Originally Posted by krabapple /forum/post/12282152


Remember too: when Mike started feeling stressed, he took a break and played some pool. And they tossed out the trial where he thought 'stress' was a factor. (I wonder if he got that one right or not?)

i never did make a choice for #6 since clearly i could not get my bearings on any differences.....it was at this point i recognized that my aural memory had reached it's limits and i needed to re-establish it.


since they had already started test #6 they decided to throw it out and go to #7 instead of re-doing #6.


with 20/20 hindsight it is evidant that my aural memory had failed by test #2....but it was not till test #6 that i became aware of that.


my future efforts will be focused on how to duplicate my performance on test #1 and #7 where my aural memory was most strong. it's also possible i was just 'lucky' on #1 and #7 and i never really heard any differences. time will tell.
 
#128 ·
Hello Mike I do not know how the test was done, but I find when doing my a/b testing with different components that a particular word or phrase in a song will have a different characteristic ie ; more emotional or better delininated. If I am trying to listen for multiple differences in a longer test setting it gets frustrating. Some pieces of course just sound better or worse and its a no brainer, but when your system is comprised of high end components the differences are subtle.
 
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