Blind Power Cord Test & results
Eldart, is not A vs B that's banned, it's DBT. It takes a while to live with something and learn its idiosincracies, though I can tell differences in A vs B comparisons pretty quickly. It's a matter of training the ear. Albert is trying to explain to you some key aspects of this subject. Take the message and let the dove fly away... *** |
QUOTEIt may be that our eyes and our brand perceptions and all of our other expectations contribute more to what we hear than we realize or care to admitQUOTE Generally speaking, of course. Not everyone is taken in by glitz and hype but unfortunately that tends to happen much too often, no doubt. Speaking for myself, and many others I'm sure, I have been pleasantly surprised in the past to prefer a much lower cost alternative. I think, as you eluded to, differences are much more evident in our own systems with which we tend to be intimately familiar with. I would not sell yourself short and certainly would not be dismayed with your performance in the test, which is most likely the least reliable in this case. |
I was part of the panel for this test. My personal results--the number of times I correctly identified if X was A or B--were dismal, and it sort of left me depressed to tell you the truth. I believe the methodology was sound. At any rate, I was satisfied with it. Please remember that the object was NOT to choose which cable we preferred, it was only to see if we could correctly identify an audible difference--we heard A, then B, then X. Was X=A or was X=B. When I make cable changes at home, this is a no-brainer. The differences are IMMEDIATELY apparent, although my long-term preference may not be. The ABX testing procedure may be flawed, but I can not dismiss the test results out of hand because they do not support my day-to-day experience as an audiophile. Nor will I abandon the hobby. I just want to know what is true. As much as the error may lie with the testing methodology, it may also lie in the ways we normally listen to components. It may be that our eyes and our brand perceptions and all of our other expectations contribute more to what we hear than we realize or care to admit. I choose to keep an open mind about this. Your mileage may vary. By the way, I just recently moved from stock power cords to aftermarket cords on my Rowland monoblocks. The difference was huge! Even if an ABX test showed me that I could not realiably tell the difference between stock and pricey, I would still make the upgrade. But I'd like to know. Not sure if it was mentioned, but the A and B in this test were generic stock cords vs. $2500 Nordost Valhalla PCs. |
Well, since it is easy to determine what differences are audible in cables, whether you use A/B, long term listening, or whatever, then use whatever method you want to, and get the cables you want. What is so hard about this? I never have any difficulty hearing the differences, whether I'm looking, or blind, or otherwise. It's simple. Why people make such a big deal about this is beyond me. There's nothing difficult about it. If a difference is heard, then there is a difference. If the difference isn't much, or doesn't seem to justify the price difference, then don't buy it. Is this too hard to understand? If you like blind tests, then use them. If you like long term listening tests, then use them. However, I would caution that most cables DO have a break-in period(whether anyone wants to admit it or not, and it is scientifically based and measureable, due at least to dielectric changes), and the cables should be allowed to have some time on them to make an honest decision. My favorite method is to take some time in listening so that the cable has at least 200 hours of break-in time. Then while listening to the same material, I take notes of likes and dislikes. I then go back to the reference set of cables and allow them to settle in and compare notes. Time will tell. Have fun and enjoy your cables in your system. |
Both long term listening and A/B comparisons are an attempt to decide if there is a difference and if that change is worth implementing on a permanent basis. For those who don't trust themselves or NEED A/B testing (for whatever reason), I say go for it. I always know what is being changed because I do my own testing, usually with a group of friends who vote on the results. Many times the outcome is not what any of us expected, so the learning process remains intact and we all evolve our systems based on priority and what we can afford. The topic of A/B is banned at Audio Asylum and I understand why. These discussions (particularly blind A/B discussions), typically follow the same evolution as this thread. Pointless arguments that do nothing to improve our systems. |
Yes, A/B comparisons are nonsense. That's why researchers studying hearing--in academia, in telecom, and even in audio--use A/B comparisons. They are trying to sabotage their own research and ensure that they will come up with meaningless results. But they're just professionals. We amateurs know better. |
Quad made a very unique device for testing componentry in a direct A vs B mode, but it doesn't work like a typical ABX type box. This device actually allows you to insert another preamp or amp in series with your existing system and switch it in and out, either in a controlled fashion for blind testing or at random, for double blind testing. This allows one to see whether the addition of another component alters the performance of the system, in what way it alters it, how stable the circuitry is as the system is changed, if the differences are both audible and repeatable, etc... From what i understand, there were only three of these devices made. I'm been working on picking one of these up for some time, it's just a matter of hooking up with the owner of this item. Sean > |
The problem with a/b testing in a controlled group is forgetting what was heard previously. Take another example: if you a/b tested digital cameras or photo printers and you laid out all the samples in front of people they would easily be able to discern differences (provided they're not color blind, which is another factor - physiology). The greens are a little lighter, the reds are more vibrant, etc. However, if you handed out the photos one at a time, the results would be different. You may be able to recall differences with each succeding photo - but two, three or four down the line and you lose your frame of reference. Even if you observe each photo for an extended period of time, you still will forget. Not the same with audio. You cannot listen to many power cables (or whatever) at the SAME time. You have to rely on your memory to discern differences since you are evaluating in succession. However, with the photo example above, just as professional photographers and graphic artists will be able to discern much more subtle color differences than the untrained eye, we can discern subtle sonic differences because of our listening experience or "training". But regardless of how good we discern sound (or color), relying on memeory is anything but accurate. And many times, we can only perceive the most subtle of differences only after living with a component for an extended period of time. Nonsense, this a/b'ing IMO. |
Although I subscribe to the A vs B method, I do note that there are some very special situations where inadudible problems might become anoying over time. The one that comes to mind is an ultrasonic oscillation that you cannot hear but which adversely affects your hearing, or perhaps gives you a headache. Very special situations. 99 percent of the time I think that A vs B will reveal any difference. And I don't see ,line cords in the category of things that would be a very special situation. |
If the difference is enough to be audible, why not stretch out the session and decide if it's worth investing in?. If you do determine there are differences between a and b, the test is over. There is no "winner", the only fact is the listener can hear a difference between a and b. At that point you are free to go and decide which you prefer, a or b. steve |
I think one of the easiest way to judge any upgrade (power cord, tube amp, or isolation device ... etc.) is to install it, listen to it, and then remove it. I'm sure all upgrades will sound different going in, It's the ones that you can't live without, when you remove from your system, that are usually the keepers. On the link thing ... if it wasn't for a good poke in the eye with a sharp stick from Sean awhile back, I wouldn't have learned how to do THIS. I think the advantage of using the mark up tags is you can check your link before posting. I can't tell you the number of times I've cut and pasted a string only to get a 404 error or "no address found", because the poster flipped something in the address. It is very frustrating looking forward to gaining some new info, and coming away with nothing. Choose your pleasure THIS or This ... http://www.audiogan.com ... try and cut and paste this link and see what happens. |
Sean, I think Dragonman was goofing wit cha. Though he probably didn't learn (or want to--hey that's cool) a thing about clip and paste, many other audiophools have. I was one. Still got a thin skin, there? The power is in ssshhhh. tacit..no response...and a bit sweeter in the beside manner department.......don't beat me up..you're a power; lose the self-righteous bravado....peace, warren Normally I would mail this to you on the aside, but you're very clear that you want all correspondences on the forum. You said to me before that open discussion concerning yours' or my dirty laundry is good for all? That's a paraphrase, not a direct quote. Something like that? Sean, this ain't a biggie... |
Dragon1952: This has nothing to do with "audio" or "snobbery". Cutting and pasting isn't a big deal, but if you want someone to look at something, the most logical thing to do is to make it easy for them to do so. Otherwise, it is kind of like saying "i've got evidence but you've got to go get it yourself if you're interested. This is where it's at, so go look at it and tell me what you think about it". Obviously, this isn't quite as simple as making it available on the spot, nor are you as likely to get as many to participate. Other than that, i use my drop-down menu somewhat like a "favourites". By cutting and pasting, it gets full of crap that i'll probably never want to visit again. Given that i like to do things that way and a few others that i know do too, and providing a link is both easy to do and more convenient for the others viewing such a thread, why not take the extra 10 - 30 seconds and provide a link? Other than that, you took the time to criticize my comments but you couldn't take the time to offer some input on the subject being discussed. What was your motive for posting such a comment to begin with and what did it accomplish? Sean > PS... What's lazier or more snobby: telling someone to fetch it for themselves and refusing to learn how to provide a link or someone that takes the time to provide a link for the convenience of others and at the same time, tries to show them how they can further their computer literacy skills? After resolving that puzzle, i think that you'll find that your original observation / comment is full of holes. |
I parted with a couple of powercords recently that I really liked. I didn't want to part with them, but it did free up some funds. Like Albert said, a quick A/B produced dramatic differences for me. The differences did not exactly diminish through long-term listening and analysis, but it allowed me time to be more sure of my decision that without the powercords my system still sounded pretty good. When I first bought the powercords, I felt that they were essential components to my system. But I stretched for an amp upgrade which improved the sound of my system. The powercords didn't exactly make a lesser difference in my upgraded system, but my system is now more listenable so I can more easily be without it. So at this point, I felt that the differences made by the powercords were not worth the cost as my system now sounds pretty good without them, but if I was to win the lottery, the powercords would definitely be worth it. Different situations warrant different decisions that's all. |
I think people are under too much pressure to make a decision when confronted with A or B. Why should a change in your audio system be based on a decision made in 10 seconds or less? Al et all, quick switching is used to determine if a difference is audible, not which of a or b you prefer. Not understanding this fact is inexcusable as it is repeated countless times and makes most of these arguments moot. Quick switching is used to determine if a difference is audible, not which of a or b you prefer. see?:) steve |
Albertporter...I don't want to get mixed up with the power cord thing, but perhaps you could explain why you think (pronounce actually) that, in general, a long term listening comparison is better than a quick A or B. In my experience long term comparisons become very subjective, so that it is easy to "hear" differences that don't really exist. I think people are under too much pressure to make a decision when confronted with A or B. Why should a change in your audio system be based on a decision made in 10 seconds or less? Have you not ever made a decision too quickly and later regretted it? If you are truly able to tell what makes you happy in that quick a comparison, I wish I had hung out with you in college. You could have helped keep me out of decisions I made, particularly with women. |
For my ears there is a very audible difference in power cords. At least from the ones I've heard for long periods of time. I do not understand the data Sean grooves on, but I know it is significant to him as well as other audiophools. For me, it always comes down to my tympanics. I trust them and they never steer me wrong. I also agreee with Albert. Short listening experiences (at least for me, depending of course on what I'm listening to) are poor justification to come to a sound conclusion. Longer listening periods are the deal. What sounds wonderful to me at first, over the longer audio haul, does not always hold up, especially after listening to oodles of music. I heard the differences immediately when I upgraded my ICs and power cords, but those differences may not have held up after longer listening. In this case, they did. It is hard not to be influenced by ads, other audiophools, and the stereo rags. Over time, however, the ole ears will hear the truth. peace, warren |
Albertporter...I don't want to get mixed up with the power cord thing, but perhaps you could explain why you think (pronounce actually) that, in general, a long term listening comparison is better than a quick A/B. In my experience long term comparisons become very subjective, so that it is easy to "hear" differences that don't really exist. I agree that long term listening is the best way to determine if you really like the sound, but, to detect changes, I think that the quick A/B is best. |
We love debating many topics here: - power cords - interconnects - vinyl vs digital - tube vs solid state If interested, one can simply conduct an experiment and observe the results for themselves. I speculate that some will hear benefits and others won't. If you do not hear any difference, sleep well with the knowledge that you have first hand experience and saved some money. If you hear a difference, sleep well knowing that when you purchase a new power cord, you have first hand knowledge of the benefits. In either case, why care about what someone else says? You have your own experience to move beyond the bickering. Personally, I have difficulty when I do not understand why something works. I did my own experiment with a power cord and observed substantial benefits in dynamics and LF response. But darn it, I don't understand why the cord makes a difference! Here is a link to my write-up: http://forum.audiogon.com/cgi-bin/fr.pl?aamps&1092099698&read&keyw&zzdominus |
Hello, I have to believe that Albert's long-term-listening procedure is what is needed because I went back and forth last week between NBS Statement and PS Audio Statement Extreme power cords on a pair of CAT JL-3 Signature amps. There is a HUGE difference in retail cost of these two products. Each time I thought there was a little more resolution with the NBS in the decay of cymbols, but switching back to the PS Audio and the decay was so natural as well. There was no discernible tonal differences and no other attributes caught my attention as have sonic differences. Either the CAT amps don't benefit from this due to their design or I just need to listen with one set of cords for a week and try another in a week or so. And then I will try this whole process again with the power cords on a pair of recently acquired Soundlab A1s against the stock power cords. Often we want "better" products to bring on improvements but if we can not hear such differences for whatever reason, then Albert said it best, "forget about it". John |
Two seniors have already said it better than I, but I simply would like to add that different results will ocur with different gear. A number of years back I had "stock" Meridian power cord from some Meridian gear that I owned and I had this power cord connected to a Moscode amp; I replaced it with a LAT Intl. power cord, the difference was immediate and without doubt. I later used the same power cord on a Mark Levinson No.383 and heard no difference when compared to its stock power cord. |
Many people who consider aftermarket AC cords snake oil are those that cannot (or will not) justify the difference the investment makes. If that is the argument, I am in complete agrement. Many tweaks in high end audio are a poor value when compared to better speakers or improving the source. However, once a system contains all the best components, with very little left to be accomplished, aftermarket AC cords as well as other premium tweaks can make a significant improvement. As stated countless times in these forums, LONG TERM LISTENING is the only way to determine if your system is right for you musically. Short listening sessions tend to confuse and do little to establish if the change provides long term satisfaction. Best to get a test cord, install it on a piece in your system that is MOST likely to benefit, usually the amp or source. Then, over time determine if that provides better sound. Best to listen for a week, then swap back to the original cord and see if you "miss" the upgrade. Be honest with yourself and don't be concerned with what you think your going to hear or what anyone else has told you. If in the end your system does not provide better performance with that aftermarket cord, replace it with another and do the test again, or put the stock cord back in the system and forget about it. In my system the results are so drastic that a single pass between two cords is all that is required. I have however, sat in front of systems that responded very poorly or not at all. It's like everything else in life, you have to work at it to determine the answer. Also, this is from the web site you linked to, appears they had concerns about the validity of the test due to time constraints, same as I suggested (above). There were several acknowledged weaknesses to the test. The number of participants and trials was not very high. Most people sat far from the sweet spot. The ideal situation, which would have allowed participants to audition A and B more than once before trying to identify X, was not possible because the length of time it would have taken to do so would have burned everyone out. (Many members of the second group said they were fried by the time 3:30 PM rolled around.) Switchers failed to turn on both amps three times, and Baci Brown of canine renown further interrupted the flow twice with scratching and barking at outside sounds and a perceived need to pee it all out in the yard. Finally, and perhaps of greatest significance, the time it took to switch cords was longer than the generally accepted 5 second length of human auditory memory. This reduced what Manny terms “the differential sharpness of perception” of participants. I suggest you test this in your own system and forget about what other write, including myself. |
Sorry for my rant here, but you guys kill me with the lack of links. The directions on how to post a link is found directly under the data input area and is labeled "No html, but you may use markup tags". Clicking on that will show you exactly how to post different types of links. If you are in the middle of a post and forget how to post a link, you can even click on the directions below you post, see how it is done and then click your web browser's "back" button to return to your post as it was. You can do this as many times as it takes with no fear of losing the data that you've already entered. http://www.hometheaterhifi.com/volume_11_4/feature-article-blind-test-power-cords-12-2004.html Other than that, i've done testing where the differences in power cabling was both highly audible and measurable. The fact that the differences were so audibly noticeable was what caused me to take test measurements. The only thing altered during the test was one power cord as fed to a digital source component. The frequency response showed measurable deviations both in the warmth region and in the extreme treble region. Other than that, i'm quite certain that spectral analysis would show differences in the noise floor of a component when comparing "optimized" power cords vs more conventional designs. Sean > |
I have not experimented with power cords myself, however, what the conclusions determined is that "We simply failed to prove that differences can be detected to a statistically significant degree using a blind ABX protocol" I have always been skeptical that audible differences could be distinguished between power cords. There's simply too many other variables when it comes to the delivery of power to the component. However, having heard the same results regarding ABX tests involving amps and interconnects, and, having myself been able to distinguish differences between these components in my own experimentation, I would certainly not rule anything out until I performed some actual experiments myself. I think that the logic in ABX testing is seriously flawed and would tend to reject any results from such tests. |
