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#1
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Darryl Miyaguchi wrote in message ...
For what it's worth, I have performed enough ABX testing to convince myself that it's possible for me to detect volume differences 0.5 dB using music, so I doubt very highly that a group test would fail to show that 1.75 dB differences on a variety of different music are not audible using a DBT. I think it's generally acknowledged that such differences are audible. Mirabel seems to be arguing that, given what he claims is a 1.75 dB difference, every member of Greenhill's panel should have scored at or near perfection, and the fact that they didn't bespeaks some flaw in Greenhill's methodology. I'm not yet convinced that there really was a 1.75 dB difference here, however. What Greenhill says about the 24-gauge cable is: "Its 1.8-ohm resistance resulted in a 1.76-dB insertion loss with an 8-ohm resistive load." How does this translate to the specific test in question, which used a recording of a male a cappella chorus (where the fundamental tones, at least, range from 60 to less than 1000 Hz)? Greenhill only level-matched a single pink noise test, and the only times he discusses levels in the article appear to be in reference to pink noise tests. E.g.: "A 1- to 2-dB decrease in sound level was measured for the 24-gauge wire during the pink noise listening tests." I freely admit that I'm out of my element here, but I don't think we can automatically assume that there was a similar difference in SPL when listening to the choral music. Hopefully, someone with some technical expertise can shed some further light on this. bob |
#2
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"ludovic mirabel" wrote in message
news:uCJLa.56660$Ab2.130013@sccrnsc01 (KikeG) wrote in message et... (ludovic mirabel) wrote in message news:bn2La.36126$Ab2.61637@sccrnsc01... I haven't read Greenhill's tests report, but it seems there's some controversy over what you are saying. Even if that was true, that would suggest there were some problems at the test, since anyone of my family could ABX that wideband level difference quite easily. Enrique (Kike For friends) Apologies for dealing just with this for the time being . It concerns intellectual honesty something I happen to be touchy about. The " Cable test's (" Stereo Review",Aug. Â'83) proctor and reporter was immaculately "objectivist" L. Greenhill- still alive and writing for "The Stereophile" Looking at the calendar, I see that in two months it will be 20 years since this test was published. Considering editing and publishing delays, it's already been 20 years since the test was done. If this were the only test that was done in the history of man, or if every other or the vast majority of DBTs that were done since then agreed with its results, then citing it would make some sense. Regrettably, DBTs and even ABX tests involving level differences have been done many times since then, and very many of those listening tests have provided far more sensitive results. Therefore, discussion of Greenhill's 1983 test as if it were indicative, representative or binding on what's happening today is futile and misleading. Anybody who wishes to do DBTs to investigate the audibility of level differences can do so easily using files they can freely download from the PCABX web site. I think it would be interesting for people to report the results they obtain with those files. IME the audibility of level differences for people with normal hearing and typical listening environments is closer to 0.5 dB than the 1.75 dB reported by Greenhill. Since individual listeners have different test environments and different ears, their results can be reasonably be expected to vary. In fact if the results didn't vary, it would suggest that there is something wrong with the test procedure since it would not be demonstrating the existence of well-known differences in individual listening acuity. However, it is equally well known that some place around level differences of 0.2 dB, nobody hears nuttin'. |
#3
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#4
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#6
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Darryl Miyaguchi wrote:
Let's keep it simple. We're audiophiles here. We're talking about MUSICAL REPRODUCTION DIFFERENCES between AUDIO COMPONENTS. I looked at your internet graphs. They mean zero to me. I know M. Levinsohn, Quad, Apogee, Acoustat not the names of your codecs. You assure me that they are relevant. Perhaps. Let's see BY EXPERIMENT if they do. In the meantime enjoy your lab work. Ludovic Mirabel Are you really telling me that you didn't understand the gist of the group listening test I pointed you to? Whether he realizes it or not, he's telling you *he* doesn't comprehend them. -- -S. |
#8
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(ludovic mirabel) wrote in message ...
We're talking about Greenhill old test not because it is perfect but because no better COMPONENT COMPARISON tests are available. In fact none have been published according to MTry's and Ramplemann's bibliographies since 1990. I gave a link to one at my previous message, related to soundcards and a DAT ( http://www.hydrogenaudio.org/index.p...hl=pitch&st=0& ). It revealed some audible differences. Soundcards and DATs are audio components, aren't they? There's another one concerning just a soundcard he http://www.hydrogenaudio.org/index.p...d6a76f1f8d0738 It finally revealed no audible differences. About Greenhill's test and level differences: PINK NOISE signal: 10 out of 11 participants got the maximum possible correct answers: 15 out of 15 ie. 100%. ONE was 1 guess short. He got only 14 out of 15. When MUSIC was used as a signal 1 (ONE) listener got 15 corrects, 1 got 14 and one 12. The others had results ranging from 7 and 8 through 10 to (1) 11. My question is: was there are ANY significant difference between those two sets of results? Is there a *possibility* that music disagrees with ABX or ABX with music? I would aoppreciate it if would try and make it simple leaving "confidence levels" and such out of it. You're talking to ordinary audiophiles wanting to hear if your test will help them decide what COMPONENTS to buy. Citing Greenhill's article, refering to 24-gauge cable: "Its 1.8-ohm resistance resulted in a 1.76-dB insertion loss with an 8-ohm resistive load". I don't know if this has been addressed before, but this 1.76 dB loss corresponds to a pure resistive load. Speakers are quite different from pure resistive loads, in the sense that their impedance varies with frequency, being this impedance higher than the nominal in most part of the spectrum. So, this 1.8 ohm in series with a real world speaker would definitely result in an attenuation below 1.76 dB over the whole audible spectrum on a wideband signal. Also, the attenuation will vary with frequency, so that max attenuation will be at the frequencies where the speaker impedance is minimum, and there will be little attenuation at frequencies where speaker impedance is maximum. So, the whole attenuation will depend on the spectrum of music used. There's a possibility that choral music has most of its content at frequencies where attenuation was not high, but it's difficult to know without having access to the actual music used and the speaker impedance curve. Said, that, I tried yesterday to ABX an 1.7 dB wideband (frequency constant) level attenuation on a musical sample. Result: 60/60 on a couple of minutes, Not a single miss. It is obvious to hear, but one could argue I'm trained. Despite that, I claim that, any person that does not have serious auditive problems, would be able to ABX a 1.7 dB wideband level difference on any kind of real-world music, being trained or not in ABX testing, just taking a couple of minutes to explain him the basics of ABX testing. Now, you make a point in that you have to be trained in ABXing to be good at it. I say that you have to be trained in *any* method you use to be good at it. Also, ABX testing per se requires little training. What takes more training is to learn to detect reliabily some kind of differences, whether you use ABX or not. Serious ABX training is required just for detecting very subtle differences, just like in every other area where high performance is required. And finally, an analogy: you can't evaluate driving comfort in cars without driving them, so you have to learn how to drive in order to evaluate driving comfort. Driving a car is the only reliable way to evaluate driving confort, whether you are good at it or not. And such... |
#9
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Darryl Miyaguchi wrote in message ...
On 1 Jul 2003 15:10:59 GMT, (ludovic mirabel) wrote: We're talking about Greenhill old test not because it is perfect but because no better COMPONENT COMPARISON tests are available. In fact none have been published according to MTry's and Ramplemann's bibliographies since 1990. I frequently see the distinction being made between audio components and other audio related things (such as codecs) when it comes to talking about DBT's. What is the reason for this? Desperate grasping at straws. True believers need some way to explain away the mountains of research that have been done on human hearing perception, so they try to pretend that comparing the sound of consumer audio components is somehow unrelated to human hearing perception. bob |
#10
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Tom said
Actually if nominally competent components such as wires, parts, bits and amplifiers have never been shown to materially affect the sound of reproduced music in normally reverberant conditions why would ANYONE need to conduct more experimentation, or any listening test, to choose between components? Simply choose the one with the other non-sonic characteristics (features, price, terms, availability, cosmetics, style...) that suit your fancy. That is the 64,000 dollar if. Tom said Examination of the extant body of controlled listening tests available contain enough information to aid any enthusiast in making good decisions. Even IF the existing evidence shows that wire is wire (and it does) how does that preclude any person from making any purchase decision? In my way of thinking it just might be useful for a given individual to know what has gone before (and what hasn't.) Well, so far I don't see it the way you do. I must at this point thanl you for the articles on this subject you sent me when I asked for the alleged body of empirical evidence that prooved your position on the audible differences of amplifiers. The "body of evidence" you sent me that constituted actual evidence, raw data, was not much of a body. Only two articles out of the six you sent had raw data ( "Can you trust your ears" by Tom Nousiane and "Do all amplifiers sound the same" by David Clark) and only the test you conducted had it in a usful table which could allow for the examination of trends such as learning curves or fatigue curves. First, this is not much of a body of evidence. Second, if we are to draw conclusions from the results we would have to conclude that some people can hear differences between amps and some amps sound idfferent than some other amps. Of course it would be a mistake to draw conclusions from those tests by themselves because they simply are not that conclusive. If what you sent me is the best evidence out there and if what you sent me is any significant portion of the much talked about "extant body of controled listening tests available" then I don't see how anyone can draw any strong conclusions one way or another. Tom said So IMO, a person truly interested in maximizing the sonic-quality throughput of his system simply MUST examine the results of bias controlled listening tests OR fall prey to non-sonic biasing factors, even if they are inadvertent. I examined the results of contained in the articles you sent me and do not find them conclusive. Unfortunately four of the six articles you sent me had no raw data to examine and only offered conclusions. Given the fact that the two articles that did offer raw data drew conclusions that I find questionable i have trouble feeling condifent about the conclusions drawn in the other articles missing the raw data. So I find the evidence to date that I have seen less than helpful in purchase decisions. |
#11
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(Nousaine) wrote in message ...
See his full text below: On 1 Jul 2003 15:10:59 GMT, (ludovic mirabel) wrote: _ I can't possibly answer separately and in detail all those disagreeing with me I have to live whatever remains to me of life.In particular I'll not get in between Mrs. Miyaguchi and Nousaine in the subargument of their own. So 4 interactive complementary answers for economy. First let's define what I am NOT saying. (No apologies for the capitals. Google doesn't allow italics or underlining) I'm NOT saying that the local variant of DBTs known as ABX is the wrong tool to use in research, with careful design,proper statistics, selected research topics and last but not least SELECTED, TRAINED SUBJECTS. I have no knowledge, opinion, interest in the particulars of such research because it does not research differences between real-life audio components. I'm NOT saying that those audiophiles who enjoy ABX and believe that they get valid results should not use it. As long as they do not think that their results are valid for anyone but themselves. ALSO as long as they keep in mind that their negative, null results are valid for them at this particular stage of their ABX training and musical experience. As long as they remember that if they do not revisit their negative results they may be shutting themselves off FOREVER from enlarging and enriching their hi-fi scope. I'm NOT , emphatically NOT saying that individuals shouldn't use methods of their choice to disguise the brand of components that they compare. I have one such method, myself which serves me well but may not suit others.. What I do object to is the belief that to "prove" your opinions re "difference" or "no difference"- a necessary preliminary to preference- (more about difference/preference in my answer to Audioguy.) one has to undergo a procedure known as ABX. Please, don't one of you tell me that "nobody says that". Speak for yourself. Every week somebody says just that in RAHE. Sometimes with a pseudo-objective semantical word games.: "But you have not had a "controlled test" (meaning ABX of course) so it is only your impression..".- as though it could be anything else. Or "Reviewers should undergo cotrolled test for credibility" as though it msde stupid reviewers into clever ones. And of course you Mr. Nousaine said it many times. There are a few unspoken assumptions here FIRST UNPROVEN ASSUMPTION: everyone performs just as well when ABXing and when listening for pleasure blinded or not blinded. Perhaps they do, perhaps they don't. In fact I presented evidence suggesting that there is MARKED DIFFERENCE in people's performance when listening to simple pink noise signal as opposed to listening to a musical signal I then asked Mr Miyaguchi a simple, straightforward question Is there a difference? Instead of of a simple YES= there is a difference (or NO- there isn't any- if anyone really wanted to play the fool) I got convoluted explanations of WHY there is , further beautified by you Mr. Nousaine. Incidentally I asked you the very same question one month ago and never got an answer. Why this dodging?. You can bet I'd get plain NO if there were NO DIFFERENCE. and EVERYBODY who performed flawlessly listening to pink noise would do just as well listening to music. But MOST performed abominably, (consistent with random guessing) when listening to music.. Explanation? Music is "more complex". Quite! And what else is new?.Most of us use our components to listen to music, not pink noise. If your test has problems with music is it the right one to assess the differences in MUSICAL performance of components? Where is the evidence ? Evidence where I come from ( see my answer to Audioguy concerning that) is EXPERIMENTAL evidence not circular arguments like : "Why shouldn't it be so? It is good enough for codecs isn't it?" I listen to music not codecs. And I need convincing that pink noise is the best way to test a component for its transient response to a cymbal, or rendition of a violin or a cello. I'd suggest to researchers:"Try again" All you can name since 1990 Mr. Nousaine are your own cable tests from 1995. Where I come from (again-sorry1) one gives the mag's name, the date, the page so that I can find out what was the design, who proctored, how many subjects, how many tests etc. Why so shy with details? You say: "Likewise the body of controlled listening test results can be very useful to any individual that wishes to make use of them to guide decisions (re component choice)" Where does one find that body? Buried in the pyramids or Alberta tar sands? Why not name a few ,recent representative offshoots?. Just to show that Consumer ABXing is any use other than for discomfiting the naive. Where are the current tests on current components?. You're not serious saying that there's nothing new under the sun. Any difference between the 24 bit and 16 bit cdplayers? Which dacs truly cope with jitter?, Are the Meridian and Tact room equalising systems different from any other equaliser? Any differences between the various digital sound processing systems. Come on Mr. Nousaine. Winning verbal contest against L. Mirabel is not everything. There is such a thing as putting more information on the table. Of course you are at least consistent, You truly believe that there is no difference between any components at all: By your lights such objectivist luminaries as Krueger and Pinkerton are pinkish dissidents: " Actually if nominally competent components such as wires, parts, bits and amplifiers have never been shown to materially affect the sound of reproduced music in normally reverberant conditions why would ANYONE need to conduct more experimentation, or any listening test, to choose between components?" And again. The profession of faith: " Examination of the extant body of controlled listening tests available contain enough information to aid any enthusiast in making good decisions." And what information is it?: " As I've said before; there are many proponents of high-end sound of wires, amps and parts ... but, so far, no one (in over 30 years) has ever produced a single repeatable bias controlled experiment that shows that nominally competent products in a normally reverberant environment (listening room) have any sonic contribution of their own. Nobody! Never! How about some evidence? I'll believe in BigFoot ....just show me the body! And I'll believe that there are no diferences between components when you prove that your "bias =controlled test" does not have biases of its own My other unanswered question to you one month ago was: Where is the evidence that untrained, unselected individuals perform identically, when comparing complex musical differences between components for a "test" as they do when they just listen. Reasoning that they should is plausible but reasoning that at least some of them don't is not irrational. Convincing, controlled experiment with random control subjects etc. is missing. Next consider the anti-common sense assumption that Tom and Dick do their DBT assignement equally well and both are an identical match for Harry. Should they? They are not identical in any other task aptitude, in their fingerprints or their DNA. If you agree that they would differ how do you justify YOUR challenges to all and sundry to prove their perceptions by ABX. Perhaps they are as hopeless as I'm at that task. Perhaps a violinist will hear differences in the rendition of violin tone when not bothered by a "test" but be a terrible subject for ABXing. Impossible? Where is your experimental evidence that this does not happen?. Where is the experimentation to show that the poor ABX test subjects would perform identically sitting and listening at home? Finally your telling ME that " I think Ludovic is "untrainable" because he will accept only answers he already believes are true" really takes the cake. .I'm not propunding any "test". You are. I have no faith to stick to. You BELIEVE in ABX. It is MY right to ask YOU for evidence. And it is your job to give it. You know it all perfectly well because you know what "research" and "evidence" mean. Why copy the tactics of those who have only ignorant bluster to offer? Ludovic Mirabel We're talking about Greenhill old test not because it is perfect but because no better COMPONENT COMPARISON tests are available. In fact none have been published according to MTry's and Ramplemann's bibliographies since 1990. This is simply not true. I have published 2 double blind tests personally, one of which covered 3 different wires subsequent to 1990. I frequently see the distinction being made between audio components and other audio related things (such as codecs) when it comes to talking about DBT's. What is the reason for this? In my opinion, there are two topics which should not be mixed up: 1) The effectiveness of DBT's for determining whether an audible difference exists 2) The practical usefulness of using DBT's for choosing one audio producer (component or codec) over another. Actually if nominally competent components such as wires, parts, bits and amplifiers have never been shown to materially affect the sound of reproduced music in normally reverberant conditions why would ANYONE need to conduct more experimentation, or any listening test, to choose between components? Simply choose the one with the other non-sonic characteristics (features, price, terms, availability, cosmetics, style...) that suit your fancy. Indeed 20 years ago, when I still had a day job, Radio Shack often had the "perfect" characteristic to guide purchase, which was "open on Sunday." I am not knowledgeable enough to decide on differences between your and Greenhill's interpretation of the methods and results. In my simplistic way I'd ask you to consider the following: PINK NOISE signal: 10 out of 11 participants got the maximum possible correct answers: 15 out of 15 ie. 100%. ONE was 1 guess short. He got only 14 out of 15. When MUSIC was used as a signal 1 (ONE) listener got 15 corrects, 1 got 14 and one 12. The others had results ranging from 7 and 8 through 10 to (1) 11. My question is: was there are ANY significant difference between those two sets of results? Is there a *possibility* that music disagrees with ABX or ABX with music? No: it just means with the right set of music 2 dB is at the threshold. Don't forget that listening position affects this stuff too. Also Mr Atkinson would say that perhaps the lower scoring subjects didn't have personal control of the switching. Even between two samples of music (no pink noise involved), I can certainly believe that a listening panel might have more or less difficulty in determining if they hear an audible difference. It doesn't follow that music in general is interfering with the ability to discriminate differences when using a DBT. Actually it simp,y shows that pink noise and other test signals are the most sensitive of programs. It may be possible to divulge a 'difference' with noise that would never be encountered with any known program material. It's also possible that certain programs, such as Arny Kreuger's special signals, might disclose differences that may never be encountered with commercially available music (or other) programs. So? I would aoppreciate it if would try and make it simple leaving "confidence levels" and such out of it. You're talking to ordinary audiophiles wanting to hear if your test will help them decide what COMPONENTS to buy. As before; you haven't ever been precluded from making any purchase decisions from scientific evidence before; why should any disclosure affect that now or in the future. Examination of the extant body of controlled listening tests available contain enough information to aid any enthusiast in making good decisions. Even IF the existing evidence shows that wire is wire (and it does) how does that preclude any person from making any purchase decision? In my way of thinking it just might be useful for a given individual to know what has gone before (and what hasn't.) I still don't know how this cannot do anything but IMPROVE decision making? See my first comments. It's too easy to mix up the topic of the sensitivity of DBT's as instruments for detecting audible differences with the topic of the practicality of using DBT's to choose hifi hardware. The latter is impractical for the average audiophile. No it's not. Just like 0-60 times, skid-pad and EPA mileage tests simply cannot be made by the typical individual that doesn't mean that they cannot be used to improve decision-making. Likewise the body of controlled listening test results can be very useful to any individual that wishes to make use of them to guide decisions. Otherwise the only information one has is "guidance" from sellers, anecdotal reports and "open" listening tests. The latter , of course, is quite subject to non-sonic influence. So IMO, a person truly interested in maximizing the sonic-quality throughput of his system simply MUST examine the results of bias controlled listening tests OR fall prey to non-sonic biasing factors, even if they are inadvertent. Who can argue with motherhood? The problem is that there are NO ABX COMPONENT tests being published- neither better nor worse, NONE. I heard of several audio societies considering them. No results. Not from the objectivist citadels: Detroit and Boston. Why?. Did they pan out? Given the two dozen controlled listening tests of power amplifiers published through 1991 doesn't it seem that no one needs to conduct more? Wires? The last test I published was in 1995. Not late enough? Why not? No manufacturer has EVER produced a single bias controlled experiment that showed their wires had a sound of their own in over 30 years. Why should one expect one now? I certainly can't do it; although I've given it my level (no pun intended) best. IOW, I can't produce an experiment that shows nominally competent wires ain't wires .... 'cuz they ain't. I can think of a couple of reasons: 1. It's expensive and time consuming to perfom this type of testing 2. The audible differences are, in actuality, too subtle to hear, ABX or not. Why bother with such a test? Why bother in performing a sound quality "test" that the manufacturers of the equipment can't produce? IF amps ain't amps; wires ain't wires and parts ain't parts then why haven't the makers and sellers of this stuff produced repeatable bias controlled listening tests that show this to be untrue? Then there is the possibility that you seem to be focussing on, ignoring the above two: 3. DBT's in general may be decreasing the ability to hear subtle differences. Actually they preclude the ability to "hear" non-sonic differences. Which of the the above reaons do you think are most likely? Moving away from the question Greenhill was investigating (audible differences between cables) and focusing only on DBT testing and volume differences: it is trivial to perform a test of volume difference, if the contention is being made that a DBT hinders the listener from detecting 1.75 dB of volume difference. Especially if the listeners have been trained specifically for detecting volume differences prior to the test. However, such an experiment would be exceedingly uninteresting, and I have doubts it would sway the opinion of anybody participating in this debate. The volume difference was just a by-effect of a comparison between cables. And yes, TRAINED people would do better than Greenhill's "Expert audiophiles" ie rank amateurs just like us. Would some though do better than the others and some remain untrainable? Just like us. I think Ludovic is "untrainable" because he will accept only answers he already believes are true. I have no doubt that there are some people who are unreliable when it comes to performing a DBT test. In a codec test using ABC/HR, if somebody rates the hidden reference worse than the revealed reference (both references are identical), his listening opinion is either weighted less or thrown out altogether. What you are describing is 'reverse significance' which is typically a inadvertant form of internal bias. For what it's worth, I have performed enough ABX testing to convince myself that it's possible for me to detect volume differences 0.5 dB using music, so I doubt very highly that a group test would fail to show that 1.75 dB differences on a variety of different music are not audible using a DBT. I can easily hear 1db difference between channels, and a change of 1 db. What I can't do is to have 80 db changed to 81 db, then be asked if the third unknown is 80 or 81 dbs. and be consistently correct. Perhaps I could if I trained as much as you have done. Perhaps not Some others could, some couldn't. We're all different. Produce a test which will be valid for all ages, genders, extent of training, innate musical and ABxing abilities, all kinds of musical experience and preference. Then prove BY EXPERIMENT that it works for COMPARING COMPONENTS. So that anyone can do it and if he gets a null result BE CERTAIN that with more training or different musical experience he would not hear what he did not hear before. And perhaps just get on widening his musical experience and then rcompare (with his eyes covered if he is marketing susceptible) Let's keep it simple. We're audiophiles here. We're talking about MUSICAL REPRODUCTION DIFFERENCES between AUDIO COMPONENTS. I looked at your internet graphs. They mean zero to me. I know M. Levinsohn, Quad, Apogee, Acoustat not the names of your codecs. You assure me that they are relevant. Perhaps. Let's see BY EXPERIMENT if they do. In the meantime enjoy your lab work. Ludovic Mirabel Are you really telling me that you didn't understand the gist of the group listening test I pointed you to? For one thing, it says that although people have different individual preferences about how they evaluate codec quality, as a group, they can identify trends. This, despite the variety of training, hearing acuity, audio equipment, and listening environment. Another point is that it would be more difficult to identify trends if such a study included the opinions of people who judge the hidden reference to be worse than the revealed reference (simultaneously judging the encoded signal to be the same as the revealed reference). In other words, there are people whose listening opinions can't be trusted, and the DBT is designed to identify them. That result identifies a form of experimental bias, does it not? The last point is that I can see no reason why such procedures could not (in theory, if perhaps not in practical terms) be applied to audio components. Why don't you explain to me what the difference is (in terms of sensitivity) between using DBT's for audio codecs and using DBT's for audio components? Darryl Miyaguchi There is no difference. It seems to me that this poster may have never taken a bias controlled listening test or, if he has, the results didn't fit with prior held expectations. It's much easier to argue with the existing evidence than prove that you can hear things that no human has been able to demonstrate, when not peeking. As I've said before; there are many proponents of high-end sound of wires, amps and parts ... but, so far, no one (in over 30 years) has ever produced a single repeatable bias controlled experiment that shows that nominally competent products in a normally reverberant environment (listening room) have any sonic contribution of their own. Nobody! Never! How about some evidence? I'll believe in BigFoot ....just show me the body! |
#12
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(Bob Marcus) wrote in message ...
(ludovic mirabel) wrote in message ... Snip. I said: I can easily hear 1db difference between channels, and a change of 1 db. What I can't do is to have 80 db changed to 81 db, then be asked if the third unknown is 80 or 81 dbs. and be consistently correct. Two questions: 1) What do you mean by "consistent"? 100% of the time, or just with statistical reliability? 2) Were you able to switch instantaneously between them? Audiophiles pooh-pooh this, but it's certainly easier to hear level differences when you can switch instantaneously. I'm not aware of any evidence that musical experience is particularly helpful in these kinds of tests. That's not what "training" is about in this context. Interesting. "We" don't "believe" that musical experience has anything to do with music reproducing components. Snip So far as I can tell, the only experiment that would satisfy you would be one that confirmed your own beliefs about what is and is not audible. I'm afraid we can't do that. bob The "instantaneous switch" is my stepped volume control. It is in working order. As for "statistical reliability"- how consistently do I hear the 1db. volume difference when I switch? 100% of the time when full range music or voice are playing. . Like everyone else not totally deaf would- Mr Myaguchi for one hears 0.5 db volume change I'm not reporting the results of a controlled lab test but my experiences. Anyone disbelieving me is free to do so. I also am not on a witness stand in court. Should I be foolish enough to engage in this exchange your next question might be: " Have you any witnesses?" "Did you say your wife? When did you stop beating your wife to get her to witness for you?" We're in an audiophile forum not in court Mr. Marcus. You will not spell your qualifications for instructing others to learn those subjects together and separately : statistics, electronics, psychoacoustics, details of medical drug research, but you're again telling me what "we' can or cannot do in those areas.. Who are those "we"? Lawyers? You're a lawyer aren't you?. Unless like in all those other areas you took one course or read one law book. As for the rest of your message; it is just a rehash of what 4 other participants said more ably and with more inside knowledge. . Read my answers to them. Ludovic Mirabel |
#13
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I said
I examined the results of contained in the articles you sent me and do not find them conclusive. Arny said This begs the question as to whether there exists any evidence that would be found to be conclusive by certain persons. By certain persons I suspect you are including me. That is an interesting question. Does such a body of evidence even exist? When Tom Nousiane made his offer of such evidence the body of evidence he offered was hardly conclusive about the audibility of amplifiers. This begs the question are some people drawing definitive conclusions with less than adequate evidence to draw such conclusions? Do you think the two cited articles supply sufficient evience to draw any definitive conclusions about the audibility of amplifiers? Do you think the evidence in those articles qualify as scientifically valid bodies of empirical evidence? Do you think the issue of test sensitivity was sufficiently addressed in those tests based on the content of those articles? I said Unfortunately four of the six articles you sent me had no raw data to examine and only offered conclusions. Arny said Would this have made a difference? It does to me when I am asking for empirical evidence. conclusions and analysis is not data. analysis and conclusions without the raw data is just opinions IMO. I said Given the fact that the two articles that did offer raw data drew conclusions that I find questionable i have trouble feeling confident about the conclusions drawn in the other articles missing the raw data. Arny said Bottom line, there are plenty of opportunities now to do your own experiments, gather and analyze your own data, etc. 1. That is irrelevant. Tom was claiming one could use the extant body of evidence to make purchasing decisions. I was addressing that claim. 2. That is not neccessarily true. Unless if we are trying to limmit this to scientifically valid tests. I said So I find the evidence to date that I have seen less than helpful in purchase decisions. Arny said The problem here relates to being able to obtain abstract knowledge and apply it. Nonsense. this is just a personal attack. Please show how I have failed to either obtain or apply absrtact knowledge in this case. Do you think Tom Nousiane has failed in his attempt to supply me with the best empirical evidence on the subject? do you think the cited tests offer evidence upon which one can draw definitive conclusions about the sound of amplifiers? Please specifically support your inference that I have failed intelectually in my edeavour to "obtain abstract knowledge and apply it" on this subject. If you can't then please retract your claims on this matter. They are offensive. Arny said Once I found that dramatic audible differences between good cables,SS amplifiers and/or CD players just don't exist; I started basing my purchase decisions on differences that do exist. Dramatic is a subjective adjective. What is dramatic to one person is insignificant to another. Maybe we should stick to the subject of audible differences. |
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Darryl Miyaguchi wrote in message ...
On 1 Jul 2003 15:10:59 GMT, (ludovic mirabel) wrote: Apologies for rearranging your text for my convenience. You say: In my opinion, there are two topics which should not be mixed up: 1) The effectiveness of DBT's for determining whether an audible difference exists 2) The practical usefulness of using DBT's for choosing one audio producer (component or codec) over another. Let me be quite brutal about this. My ONLY concern and interest is in part 2. I'm reading and participating in RAHE not because I'm interested in psychometric research but exactly for help to "choose one audio producer over another". And the "producer" that I'll use in my listening room is not codec but a musical reproducing device. I may just as well tackle the question of codec or any other artefact/ vs. a musical audio device. Are they different? I don't know. You challenge me below to demonstrate why they shouldn't behave identically. The shoe is on the other foot- you have first to show that they would. I'll have to explain something he Basically I come from a different corner of science from yours. Mine is applied science not basic research. You ask me why codex shouldn't act like amplifiers. Maybe they do. But till there is a convincing experiment to show that it is so, to me it is just more inference, reasoning by analogy. For millenia physicians reasoned, speculated and looked at analogies. The diseased blood is full of noxious miasmas so let's bleed poor Lord Byron to death. Sometime in the XXth century things changed. The question to ask became not: "Is it likely to work because Herr Professor thinks it should or because there are "good reasons" why it should? or what not. It became: "Can I design an experiment to show if it will or will not WORK ?" Reasoning and speculation be damned in medical research- coarse practicality culminating in Random controlled Double Blind testing rules. Patient's answers, doctor's impressions are collected for documentation- the outcome is decided by demonstrable physical changes. All that I said before, But now I come to Codex vs Amplifier. No matter how close the analogy you make it means nothing in the applied medical research. Add one hydrogen binding to a life saving drug and it becomes a killer. Of course the Rhinoceros are being exterminated because the upright horn is a cure for impotence in China. An unfair (I confess) reductio ad absurdum of reasoning by analogy: " Why shouldn't the horn work? It looks like IT doesn't it?" I said: I am not knowledgeable enough to decide on differences between your and Greenhill's interpretation of the methods and results. In my simplistic way I'd ask you to consider the following: PINK NOISE signal: 10 out of 11 participants got the maximum possible correct answers: 15 out of 15 ie. 100%. ONE was short of 100%t. He got only 14 out of 15 But when MUSIC was used as a signal 1 (ONE) listener got 15 corrects, one got 14 and one 12. The others had results ranging from 7 and 8 through 10 to 11.(one) My question is: was there are ANY significant difference between those two sets of results? Is there a *possibility* that music disagrees with ABX or ABX with music? You answered: Even between two samples of music (no pink noise involved), I can certainly believe that a listening panel might have more or less difficulty in determining if they hear an audible difference. It doesn't follow that music in general is interfering with the ability to discriminate differences when using a DBT. Sorry, but the questiion is a simple one :"Did THIS panel perform differently on pink noise and music or not?" And the answer should be simple: Yes or No. Once you answer that you can give your qualifiers, explanations and so on.. You said: It's too easy to mix up the topic of the sensitivity of DBT's as instruments for detecting audible differences with the topic of the practicality of using DBT's to choose hifi hardware. The latter is impractical for the average audiophile. As I said before the only topic I'm interested in is exactly the "practicality" of its use for comparing components. Were I interested in DBT sensitivity for other *audible differences* I'd be reading JAES or a "Journal of Psychometrics" (if there is such a thing) -not RAHE. But your last sentence certainly rings true- that's why your getting in hot water with the Old Believers is to be expected. You said that good ABX component tests are possible (paraphrase). I answered: Who can argue with motherhood? The problem is that there are NO ABX COMPONENT tests being published- neither good nor bad, NONE. I heard of several audio societies considering them. No results. Not from the objectivist citadels: Detroit and Boston. Why?. Did they not pan out? Your answer: I can think of a couple of reasons: 1. It's expensive and time consuming to perfom this type of testing 2. The audible differences are, in actuality, too subtle to hear, ABX or not. Why bother with such a test? Then there is the possibility that you seem to be focussing on, ignoring the above two: 3. DBT's in general may be decreasing the ability to hear subtle differences. Which of the the above reaons do you think are most likely? If you ask me : the last one. Enough changed in audio since 1990 to spur newer comparisons. (See my posting to Mr. Audio Guy). It is expensive but not beyond the possibilities of such as Boston Audio Socy. I saw the design of a Seattlee AUDIO Socy AbX test. Then silence. No results. Was it your reason 3.? I don't know and I never , never speculate. Especially since the stock market expired. If it works why don't people do it? You asked: Are you really telling me that you didn't understand the gist of the group listening test I pointed you to? For one thing, it says that although people have different individual preferences about how they evaluate codec quality, as a group, they can identify trends. This, despite the variety of training, hearing acuity, audio equipment, and listening environment. Another point is that it would be more difficult to identify trends if such a study included the opinions of people who judge the hidden reference to be worse than the revealed reference (simultaneously judging the encoded signal to be the same as the revealed reference). In other words, there are people whose listening opinions can't be trusted, and the DBT is designed to identify them. Re "trends and statistical averages:" How "likely" am I to hear those musical differences under ABX that I heard without it? As likely as the 72% of Greenhill's subjects who failed at a much simpler task when being ABXed?. Or do you have any other experimentally proven statistics? Let me say something about statistics as applied to prognosis ( outcome forecasting) in medicine. A patient has inoperable lung cancer. His family want to know how long he'll live. If you're a heartless fool you say: "average survival with this is 6 months." If you're a clever and humane physician you say:" Whatever I'll say you'll probably want to check in the Public Library anyway- you'll find a 6 months AVERAGE survival rate . But you husband's name is Joe Smith not Joe Average. Some die in a few weeks, some in a couple of years and some-very, very few have an unexplainable, complete disappearance of the growth. I can not tell exactly how long your husband will live, but more likely months than years." A "test" which depends on statistics can not be used as a universally recommended method of differentiation. It may be O.K. for some and worse than useless for the others. And the devil is that no one can tell if he is being deceived by it when he gets a null result because he may perform differently in 6 months time or when not bothered by ABX. Or not. Do it at your own risk. Like choosing a book to read, a movie to attend or wine to drink. Nobody pesters you with a" test" there. Sorry, "trends" are good for public opinion polls, not as guidance for inndividuals. The last point is that I can see no reason why such procedures could not (in theory, if perhaps not in practical terms) be applied to audio components. Why don't you explain to me what the difference is (in terms of sensitivity) between using DBT's for audio codecs and using DBT's for audio components? I will not repeat why I consider the above an example of reasoning by similarity and analogy without experimental evidence. And THAT YOU fail to supply. Once you do that I'll see if the experiments were well designed, properly carried out, had good controls and so on. Ludovic Mirabel |
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On Fri, 04 Jul 2003 17:40:00 GMT, (ludovic
mirabel) wrote: Darryl Miyaguchi wrote in message ... On 1 Jul 2003 15:10:59 GMT, (ludovic mirabel) wrote: Apologies for rearranging your text for my convenience. You say: In my opinion, there are two topics which should not be mixed up: 1) The effectiveness of DBT's for determining whether an audible difference exists 2) The practical usefulness of using DBT's for choosing one audio producer (component or codec) over another. Let me be quite brutal about this. My ONLY concern and interest is in part 2. I'm reading and participating in RAHE not because I'm interested in psychometric research but exactly for help to "choose one audio producer over another". And the "producer" that I'll use in my listening room is not codec but a musical reproducing device. Your claim is that DBT's reduce the ability to discriminate differences in music using audio components. This is a very specific claim which relies upon several assumptions: 1. DBT's reduce, in general, the ability to discriminate differences. Some evidence to the contrary: ABX has been successfully used to differentiate truncation vs. dithering at 16 bits: http://ff123.net/24bit/24bitanalysis.html ABX has been successfully used to discriminate volume differences in music of less than 0.5 dB (personal tests). 2. ABX may be ok for pink noise, but not for music. A controlled test (Greenhill's) showed decreased listener sensitivity when choral music was presented instead of pink noise. From this you infer that ABX is not suited for music. Again, I must point out that this inference is flawed. The simpler and more likely explanation is that all types of listening methods (included sighted listening) are affected by musical selection. 3. DBT's may be ok for audio codecs, but not for comparing audio components. We seem to disagree on this basic point, although I will point out that you can hardly claim that the onus is on me to provide evidence that the two situations are similar. If I assume a certain position (that the human ear/brain behaves similarly, according to the same psychoacoustic descriptions, regardless of the audio source), then your position is surely an assumption as well, and IMO more speculative. I choose the null hypothesis (there is no difference) until I see evidence to the contrary. Sorry, but the questiion is a simple one :"Did THIS panel perform differently on pink noise and music or not?" And the answer should be simple: Yes or No. Once you answer that you can give your qualifiers, explanations and so on.. See my separate post to this. cut 3. DBT's in general may be decreasing the ability to hear subtle differences. Which of the the above reaons do you think are most likely? If you ask me : the last one. Enough changed in audio since 1990 to spur newer comparisons. (See my posting to Mr. Audio Guy). It is expensive but not beyond the possibilities of such as Boston Audio Socy. I saw the design of a Seattlee AUDIO Socy AbX test. Then silence. No results. Was it your reason 3.? I don't know and I never , never speculate. The irony of this statement must have escaped you. As far as I can tell, your position *is* speculative, given that it is based on very specific assumptions (see above). Especially since the stock market expired. If it works why don't people do it? cut A "test" which depends on statistics can not be used as a universally recommended method of differentiation. It may be O.K. for some and worse than useless for the others. And the devil is that no one can tell if he is being deceived by it when he gets a null result because he may perform differently in 6 months time or when not bothered by ABX. Or not. Do it at your own risk. Like choosing a book to read, a movie to attend or wine to drink. Nobody pesters you with a" test" there. Sorry, "trends" are good for public opinion polls, not as guidance for inndividuals. Hearing perceptions are more similar from person to person than their preferences in books or movies or taste in wine. If they weren't, people wouldn't have been able to design audio codecs, which rely upon universal characteristics of human hearing. However, it is true that people have varying ability to hear certain things, and that this variation affects their preferences. There are two answers to the question "Which sounds best?" One answer is the one each individual gives after personal audition. The other answer is based on group results. Which answer one should choose is based on the particular circumstance. Darryl Miyaguchi |
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I have no "evidence" for my perception that silver wires a la Kimber
sound better- TO ME- than copper (even when I'm blinded). None that would satisfy you and none, in truth- that would satisfy a critical peer-review. MORE- I don't believe that such "evidence" is possible outside of RAHE wishful fantasies. I don't believe that there is experimental evidence (see my answer to Nousaine) that a technique, such as the audio version of DBT has been shown to be capable of invalidating mine or anyone else's perceptions. I have to take issue with this claim. Any claims that suggest a physical manifestation of any phenomenon is a testable claim. If you claim to hear differences it is a testable claim. |
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(Stewart Pinkerton) wrote:
Ludovic Mirabel, for instance, has posted thousands of lines of text in various attempts to discredit what evidence exists to support the notion that 'wire is wire', and that, by and large, 'amps is amps', yet he has offered absolutely *zero* evidence to support his own beliefs. Obviously, your "evidence" is NOT sufficient to convince anyone (who does not already believe) that "amps is amps" and "wire is wire". I would suggest that any "evidence" LM and those on the other side of this debate would show YOU (or have shown you) would be insufficient to convince you, since you have long ago made up your mind. So what exactly do you hope to accomplish by continuing this endless "debate"? Isn't one definition of "insanity", 'continuing to repeat the same behavior, but expecting a different result'? Regards, Mike |
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Darryl Miyaguchi wrote:
On 3 Jul 2003 02:52:02 GMT, (Nousaine) wrote: Perhaps we're missing each others points here. With the common ABC/Hr protocol the listener is asked to identify one alternative as being the same as the reference and to grade the alternative on a downward rating scale. If I'm taking your point correctly those listeners that reliably rate an alternative as being worse than itself have responses thrown out. If so, this could be a conscious form of subject bias. But it could also be a form of experimental bias where some form of other identification cue is involved. In either case SOME form of bias is present; just as 'reverse' significant results in common A/B Same/Different or even ABX tests would indicate. Backward significance is always an indictator that some form of bias is present. Just so that we don't misunderstand exactly what is happening during one of these comparative tests: Note the implementation of ABC/Hr being used: http://ff123.net/abchr/abchr.html The reference is not being presented as another codec. In the process of rating each codec, the listener must choose from the hidden reference. Yes, the hidden reference is the original unprocessed source. This is different from MUSHRA, where there is a hidden reference, but which is typically presented as another codec. I think we're both on the same page when talking about ABC/Hr, but I just want to make sure. When I speak of a bias, I am mostly concerned that one codec is not falsely preferred over another. In the ABC/Hr implementation we're discussing, suppose a listener downrates the hidden reference for one or more codecs. Such a listener is not an *outlier* -- he is clearly *incorrect*. Then, the procedure used would be to discard that particular listener's entire set of results for all codecs. I don't believe there is a preferential bias of the type I am concerned about. Instead, I believe that what is happening is that statistical noise is being reduced when unreliable listeners are removed, but possibly sensitivity is being reduced as well for the reasons I outlined in my previous post. Reduced sensitivity is ok for the purposes of this experiment; preferential bias is not. Actually in the ABC/Hr protocol any listener reliably rating the hidden reference worse than itself has demonstrated SOME form of test or subject bias. Ther eis no other explanation; either the protocol has some form of non-sonic confounding identifier OR the subject can truly hear the difference and is purposefully responding in a backward manner. I'm all for rejecting biased data but any kind of significant "reverse" results shoyld be followed by an examination of the experiment to find whether it's specific to a given subject(s). If the latter cannot be shown then the entire experiment can be ruled invalid. Now, one could argue that this procedure is selecting a special group out of the test population. If one of the purposes of the experiment is to represent a certain listening population, then throwing out unreliable listeners is changing things. However, this particular test makes no pretensions of representing the average listener. The people who participate in this type of experiment are already self-selected, and likely to be more sensitive than the average Joe. Most likely true. Is there some mechanism whereby you think that some sort of bias (falsely preferring one or more codecs over others) may be operating if unreliable results of the type described are thrown out? I can't think of any. Darryl Miyaguchi As I said earlier if you cannot determine that results were limited to a given subject(s) then the whole experiment must be considered suspect. At the very least it should be repeated. |
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I said
By certain persons I suspect you are including me. That is an interesting question. Does such a body of evidence even exist? When Tom Nousiane made his offer of such evidence the body of evidence he offered was hardly conclusive about the audibility of amplifiers. Tom said Please don't make up things that I didn't offer. Well here is what the record shows "Tom said Yes, of course. I have spent the time and money to acquire all I can about listening tests and what they show. My copy of the Proceedings wasn't free; so are you expecting me to send you or Scott a free copy? I've done the same formany. Just ask. I said Consider it asked. Tom said snail mail address please." Maybe I am missing something but that looks like such an offer to me. Tom said You said you had never seen ANY evidence about the audibility of amps, wires and parts. I offered to send you one such report. Indeed one of the ones I did send you lists a couple dozen amp experiments. I said I have never seen any scientifically valid empirical evidence on the matter.You sent six articles only two of which had the raw data I was asking about.The two that had raw data had not been published in a peer reviewed scientific journal so they do not qualify as scientifically valid. It was nice of you to send the six articles. Thank you. In light of the fact that I was asking about *any scientifically valid empirical evidence that supported your position on the audibility of amps*. My comments on the two articles that actually had raw data stands. I don't recall any limmits of only one report. Tom said What I find interesting is that not ONE credible, replicable bias controlled report verifying the audibility of nominally competent amps, wires or capacitors in normally reverberant conditions exists. Not one. What I find interesting is the best *evidence* you sent me on the matter was IMO inconclusive. Some of the evidence in the Clark article suggested that perhaps some people can hear differences and that some amps tested sounded different to other amps tested. So how do you deal with that? Do you acknowledge the test was inconclusive which is what I see or do you claim the test gives us scientifically valid empirical evidence upon which we can draw definitive conclusions? I said This begs the question are some people drawing definitive conclusions with less than adequate evidence to draw such conclusions? Do you think the two cited articles supply sufficient evience to draw any definitive conclusions about the audibility of amplifiers? Tom said Find a credible one that suggests otherwise, why don't you? The article on the Clark tests certainly did suggest that some people can hear differences and that some amps sound different than others. I said Do you think the evidence in those articles qualify as scientifically valid bodies of empirical evidence? Do you think the issue of test sensitivity was sufficiently addressed in those tests based on the content of those articles? Tom said Yes. Definitely. How? There was no scientific peer review. Are you going to ignore the protocols of the scientific world? I think issue of test sensitivity in both cited articles were quite poorly addressed. So much so that one can draw multiple conclusions from the results such as the listeners may have not been sensitive enough. The setup may not have been releavling enough etc. A bad mistake IMO. I said Unfortunately four of the six articles you sent me had no raw data to examine and only offered conclusions. Arny said Would this have made a difference? I said It does to me when I am asking for empirical evidence. conclusions and analysis is not data. analysis and conclusions without the raw data is just opinions IMO. Tom said The statemrnt about lack of data is simply not true. Yes it is. Only two of the articles had the raw data. Tom said All the reports sent to him contained raw data. Straw man. I said "the raw data" which implies all of it. Only two of the six did this. Heck some of the articles had no raw data. Tom said The other was a compilation of results from a couple dozen previously conducted amplifier tests. Right. They were an analyisis of data that was not presented in the raw. That was exactly what I did not want as I already explained. Tom said All Mr Wheel has to do is look them up. As if this is an easy and cost free task. We've been down this road before. I have been on too many fruitless Easter egg hunts on this subject. If those claiming the existance of evidence cannot provide it than it is unreasonable for them to expect me to go find it IMO. Tom said But again he originally suggested that no evidence on the matter, one way or another, actually existed. Baloney! Never suggested it. Cite your proof or withdraw the claim please. It is a misrepresentation of anything I said or believe. Tom said At the very least one should recognize that plenty of it exists, that interested parties have had public access to same over the past 30 years and that you can't find a single experiment that supports the claimed audibility of amps and wires. All I have done is ask to see it. To date not much has been shown to me and what has been shown is hardly something one could base any definitive conclusions upon. What you sent me did not prove your position at all. Tom said What's funny is that Mr Wheel examines the raw data and rejects the conclusion "no single listener was able to reliably identify amps under blind consitions" that the data clearly depicted. Wrong.In the Dave Clark test listener #2 got 30/48 correct with a statistical relaibility of hearing a difference of 94% Listener #6 got 26/48 with a statistical probablity of 84% chance of hearing differences. Listener #15 got 15/21 correct with an 81% chance of hearing a difference. Given the fact that no tests were done to measure listener's hearing acuity and no tests were done to varify test sensitivty to known barely aduible differences one cannot conclude anything other than those listeners may have heard differences. Bell curves have no meaning without data on the listener's hearing acuity. The logicqal thing would have ben to do follow up tests on those listeners to see if it was just a fluctuation that fits within the predicted bell curve or if they really could hear differences as the results suggest. Hence there is no conclusive evidence from this test that as you say"no single listener was able to reliably identify amps under blind conditions. Further more many different amps were used in this test. If some do sound the same and some do sound different this will have an affect on everyone's score and the bell curve.For example a Counterpoint amp was compared to an NAD amp and the results of 30/48 correct answers with a probablity of 94% that a difference was heard. Yet no follow up was done on this comparison. Arny said Bottom line, there are plenty of opportunities now to do your own experiments, gather and analyze your own data, etc. I said 1. That is irrelevant. Tom was claiming one could use the extant body of evidence to make purchasing decisions. I was addressing that claim. 2. That is not neccessarily true. Unless if we are trying to limmit this to scientifically valid tests. Tom said I've been making high quality decisions based on this evidence for a quarter century. I believe you believe that. I said So I find the evidence to date that I have seen less than helpful in purchase decisions. Tom said Those who will not see and won'y examine historyt are doomed to repeat historical mistakes Something politicians should pay attention to. We are not talking history here we are talking evidence. If you can find fault with my analysis of the evidence that we have discussed please cite it and prove it. |
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Mkuller wrote:
(Stewart Pinkerton) wrote: Ludovic Mirabel, for instance, has posted thousands of lines of text in various attempts to discredit what evidence exists to support the notion that 'wire is wire', and that, by and large, 'amps is amps', yet he has offered absolutely *zero* evidence to support his own beliefs. Obviously, your "evidence" is NOT sufficient to convince anyone (who does not already believe) that "amps is amps" and "wire is wire". I would suggest that any "evidence" LM and those on the other side of this debate would show YOU (or have shown you) would be insufficient to convince you, since you have long ago made up your mind. So what exactly do you hope to accomplish by continuing this endless "debate"? You might want to ask the person who *STARTED THE THREAD*. hint: he's on *your* 'side' -- -S. |
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Ludonvic said
I have no "evidence" for my perception that silver wires a la Kimber sound better- TO ME- than copper (even when I'm blinded). None that would satisfy you and none, in truth- that would satisfy a critical peer-review. MORE- I don't believe that such "evidence" is possible outside of RAHE wishful fantasies. I don't believe that there is experimental evidence (see my answer to Nousaine) that a technique, such as the audio version of DBT has been shown to be capable of invalidating mine or anyone else's perceptions. I said I have to take issue with this claim. Any claims that suggest a physical manifestation of any phenomenon is a testable claim. If you claim to hear differences it is a testable claim. Ludvic said Mr.S888wheel. Did you just wake up? No. Ludvic said Everything is testable - IF you have a way, a test, a method of doing it. Just that tiny, unimportant point. There are available methods to test your claim. Ludvic said If I say that there must be life somewhere in the universe outside of Earth it is testable claim if you have a test. Bad analogy. That claim is not testable do to the lack of resources. your claim of audibility is a specific claim that does not require an investigation beyond human resources. Ludvic said And it is the existence of such a test for audio components that we've been debating here for the last two years. I believe you have been debating the merits of ABX testing. One could test your claims scientifically without using ABX or doing anything to interupt the conditions under which you claim to hear differences. Ludvic said If you have a test for personal difference/preferences in cables, poetry, music, novels and wine out with it. You'll make billions selling it to the profilers who'll be spamming you and me till the end of our days. Maybe thanks to you they'll find out that , sadly, I'm past interest in their favourite topics and stop trying to titillate me in vain. Ludovic Mirabel I know that you're a serious guy but, please, for once give up. Believe me; frustration only lies this way. I have proposed such tests but I don't expect to make money off them. What I proposed is not easy to do and not practical for the garden variety of audiophile. Just becuase evidence hasn't been obtained does not make it unobtainable. |
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Tom said
Actually if nominally competent components such as wires, parts, bits and amplifiers have never been shown to materially affect the sound of reproduced music in normally reverberant conditions why would ANYONE need to conduct more experimentation, or any listening test, to choose between components? Simply choose the one with the other non-sonic characteristics (features, price, terms, availability, cosmetics, style...) that suit your fancy. I said That is the 64,000 dollar if. Tom said Examination of the extant body of controlled listening tests available contain enough information to aid any enthusiast in making good decisions. Even IF the existing evidence shows that wire is wire (and it does) how does that preclude any person from making any purchase decision? In my way of thinking it just might be useful for a given individual to know what has gone before (and what hasn't.) I said Well, so far I don't see it the way you do. I must at this point thanl you for the articles on this subject you sent me when I asked for the alleged body of empirical evidence that prooved your position on the audible differences of amplifiers. Tom said I said that a body existed. I offered to send you Some of the existing evidence because you said that you hadn't seen "any." And I thank you again for doing so. Maybe you missed the part where I said "so far" which was meant to imply that I haven't seen all the evidence to be seen. I said The "body of evidence" you sent me that constituted actual evidence, raw data, was not much of a body. Only two articles out of the six you sent had raw data ( "Can you trust your ears" by Tom Nousiane and "Do all amplifiers sound the same" by David Clark) and only the test you conducted had it in a usful table which could allow for the examination of trends such as learning curves or fatigue curves. Tom said Let's be clear here. I did not offer to send you "the" body of evidence. You'll see "The Great Debate; Is Anybody Winning" a list of over twenty controlled listening tests on amplifiers conducted prior to 1990. Sorry for the misunderstanding. I didn't mean to imply that you have sent me all the evidence that exists on the subject. Tom said As to raw data "The Great Chicago Cable Caper" and "To Tweak or Not To Tweak" both contained raw data. The copy you sent me of "The great Chicago Cable Caper" doesn't really address the issue of the audibility of amplifiers. I mistakenly identified "can you trust your Ears" with "To tweak or not to Tweak". "Can you trust your ears contains no raw data. I said First, this is not much of a body of evidence. Second, if we are to draw conclusions from the results we would have to conclude that some people can hear differences between amps and some amps sound idfferent than some other amps. Tom said None of the raw data suggests that. Sure it does unless you consider a 94% probaility that a difference was heard to to suggest that no difference was heard. I said Of course it would be a mistake to draw conclusions from those tests by themselves because they simply are not that conclusive. If what you sent me is the best evidence out there and if what you sent me is any significant portion of the much talked about "extant body of controled listening tests available" then I don't see how anyone can draw any strong conclusions one way or another. Tom said What is so funny is that I offered to send you copies of some data because you claimed to have not seen ANY of the approximately 3 dozen controlled listening tests that had been published in popular journals over the years. I didn't offer to send you all data that exists. Why is that funny? Tom said If you were truly interested you should do some of your own homework. I have been. You sending me articles on test and me reading them and analysing them is doing homework. Tom said But it certainly doesn't seem that you do have a true interest. You are entitled to your opinions about me. but it seems that they hinge on whether or not I agree with you. that appears to me to be quite unfair and unreasonable. Tom said And you're missing an important point; no one has produced a single repeatable experiment in normal listening conditions where nominally amps, wires or parts have been shown to have an audible effect. It is only important if it is taken out of context. That context being the body of repeatable experiments that have produced definitive nulls that have been thouroughly and properly investigated when some results suggest that some people may have heard differences and that some equipment may have sounded different. Further,one cannot ignore the lack of controls of test sensitivity when drawing conclusions. Unless you have demonstrated that under the given test conditionas the listener can distiguish known barely audible differences you have not eliminated the possibility of insensitivity on the part of the listener in the given test or the inability of the system used to reveal such differences. Tom said The ONLY existing evidence on your side for amplifiers is pcabx which uses a overly sensitive microscope-like technique that doesn't represent the typical sighted conditions where 'amp differences' are often made. My side? The moment one takes sides they are in deep water IMO. My side, as it stands, is I haven't seen relaible scientifically valid proof either way. I have now seen two documented tests that never were peer reviewed and failed to establish test sensitivity and had mixed results upon which no definitive conclusions could reasonably be drawn.Yes I claim to hear differences between amps here at home but I don't claim those are scientifically valid claims and I can be wrong. Tom said So IMO, a person truly interested in maximizing the sonic-quality throughput of his system simply MUST examine the results of bias controlled listening tests OR fall prey to non-sonic biasing factors, even if they are inadvertent. I said I examined the results of contained in the articles you sent me and do not find them conclusive. Unfortunately four of the six articles you sent me had no raw data to examine and only offered conclusions. Tom said Again, all of them contained raw data except for the summary piece which listed over twenty reports that you can track down if you have interest. Nope. Only the two articles had raw data. Sorry that I misidentified one of them. I said Given the fact that the two articles that did offer raw data drew conclusions that I find questionable i have trouble feeling condifent about the conclusions drawn in the other articles missing the raw data. So I find the evidence to date that I have seen less than helpful in purchase decisions. Tom said So you will reject any data that doesn't support your prior held conclusions. I haven't "rejected" any data so far. I do have issues with the lack of testing for sensitivity which leaves any null results open to different interpretations but I have not rejested any data because It didn't support any of my preconceptions. I haven't rejected any data in those two tests. Tom said I figured that would be your position. You are sadly mistaken about my position. Tom said Why not try to find ANY credible data that does? Happy hunting. If you consider the data you sent me I would suggest that a listener was hearing differences and a piece of equipment was being heard as different with a 94% probablity as credible then look no further. But I think the reasonable analysis of those two tests would be that one cannot draw any strong conclusions one way or another without follow up tests with those listeners that seemed to be hearing a difference or those pieces of equipment that seemed to be sounding different fom each other. |
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"Mkuller" wrote in message
news:hEENa.14984$I8.6569@rwcrnsc53 (Stewart Pinkerton) wrote: Ludovic Mirabel, for instance, has posted thousands of lines of text in various attempts to discredit what evidence exists to support the notion that 'wire is wire', and that, by and large, 'amps is amps', yet he has offered absolutely *zero* evidence to support his own beliefs. Obviously, your "evidence" is NOT sufficient to convince anyone (who does not already believe) that "amps is amps" and "wire is wire". This is an incredibly global statement that disqualifies itself simply on the grounds of how unqualified it is. Many people who once believed that amps mostly sounded different, have come over to the "amps is amps" viewpoint, myself included. It can be argued that the midfi audio market wouldn't exist if everybody believed that all amps sounded different and only the really high priced amps sounded good. I would suggest that any "evidence" LM and those on the other side of this debate would show YOU (or have shown you) would be insufficient to convince you, since you have long ago made up your mind. This statement ignores the existence of people such as Marcus, Nousaine and I who were formerly in the " amps mostly sound different" camp. So what exactly do you hope to accomplish by continuing this endless "debate"? Ask the people who start threads like this. The google record shows that this thread was started with the following post: http://www.google.com/groups?selm=bc...s1.newsguy.com The author is clearly identified to be someone who is clearly AGAINST the "amps is amps" viewpoint. This simple fact demolishes any argument that might be made along these lines. It appears to me that some people need to do their homework before posting. Isn't one definition of "insanity", 'continuing to repeat the same behavior, but expecting a different result'? Case in point, I do believe! |
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(ludovic mirabel) wrote in message news:n7IKa.24750$Bg.13287@rwcrnsc54...
(Dick Pierce) wrote in message news:KalKa.16012$R73.2926@sccrnsc04... Well, the answer is VERY simple: DBT does not deliver what people like Ludovic want. It does not support THEIR agenda, it does not validate THEIR preferences, indeed, it does not elevate their preferences to the level of universal fact. Science certainly works hard to give you answers, it just doesn't give a sh*t whether you like the answer or not. What delicate feelings! what restraint! Only 3 letters out of 4. THAT'S why DBT doesn't work: because it does. Here comes the heavy artillery: "SCIENCE' gives the answers. Mr. Pierce knows them. And I'm supposed not to like them. Exactly which answers to what? CDs are "better" than lps.? Transistors are "better" than tubes.? Yamaha transistor amp. is "better" than VTL.? Mr. Ludovic shows us here that he is in the "enviable" position of not being constrained by facts or information. No, unlike the rest of us in this universe, he gets to make his "facts" up. Indeed, he gets to make "facts" up about other people as well. We see here a classic existance proof of this. HIS claim, which he makes VERY evident above, is that I "know" that "CD's are better than LPs." That's very curious, because I have never said that. His claim is that I "know" that "transistors are better than tubes. That's very curious, because I have never said that. His claim is that I "know" that "Yamaha transistor amp. is better than VT: [sic]." That's very curious, because I have never said that. From whence does Mr. Ludovic achieve the ability, the privilege and, indeed, the mandate to simply make stuff up and claim I or anyone else "knows?" There are several possibilities: 1. Ludovic occupies a unique and privilieged place in the world, where he is privvy to information that NO ON ELSE knows about. 2. Ludovic simply made this stuff up. In either case, it would seem that Mr. Ludovic has exempted himself from the normal conventions of connecting claims about what others think and know to what they actually think and know. I shan't suggest this is anti-scientific or anything high-falutin' like that. I'd posit, instead, that Ludovic simply engages in a continuous stream of misrepresentation. Why? 1. It's inadvertant. He doesn't no better. Poor Ludovic. Poor us for having to slog through his irrelevant misrepresentations. 2. It's deliberate. He has no sound foundation for whatever the hell it is he's arguing about and simply to keep his side of the conversation going, he just makes stuff up because he has absolutely nothing to contrinute of any relevance or substance. The evidence, especially in the form of the quoted text above, would seem to have one lean in the direction of deliberate and malicious misrepresentation. Frankly, I don't care. He has been one of the most voluminous posters to rec.audio.high-end, and if you subtract the mis- representations and the irrelevancies and the excess verbiage and the seemingly unending repeations thereof, he is at the same time one of the least relevant contributors. Science, as in the process of advancing knowledge, could care less about Ludovics' preferences. It has no feeling, has no agenda. That's why DBT's don't agree with what Ludovic wants. It's not supposed to. It ain't about picking Yamaha amps over VTL amps, tubes over transistors, CDs over LPs, Stradivarii over Roland synthesizers, despite Ludovic's misguided and continuously unsuccessful attempts to force it into that utterly innapropriate arena. If science had feeling, it'd probably be laug Answers from "measurements"? I let the scientists like yourself (and eg. Mr. Atkinson of The Stereophile) argue as to exactly whose "measurements" prove what.I understand enough to glimpse that people with degrees in electronic engineering differ on those issues. Who am I to decide whose measurements are "better"? The sciences I am familiar with rely on experiment. I know of none that provide "scientific", experimental evidence about my preferences or yours. And, dear Mr. Pierce, for lack of anything better I'm happy with mine, do not ask you or anyone else to share them with me,(in fact I might not even like it if you did) and certainly, most definitely do not want or expect "scientific" support for them. What on earth gave you the idea that I do? Ludovic Mirabel |
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Darryl Miyaguchi
wrote: On 5 Jul 2003 20:25:01 GMT, (Nousaine) wrote: Actually in the ABC/Hr protocol any listener reliably rating the hidden reference worse than itself has demonstrated SOME form of test or subject bias. Ther eis no other explanation; either the protocol has some form of non-sonic confounding identifier OR the subject can truly hear the difference and is purposefully responding in a backward manner. Typically the listener doesn't always pull down the slider for the hidden reference, but does it once or twice out of a total of 5 or 6 groups. If the listener were to pull the reference for every codec, or if he were to pull the reference for the same codec every time he repeated the entire comparison (i.e., if it was "reliable" in some way), I would certainly become suspicious. I'm all for rejecting biased data but any kind of significant "reverse" results shoyld be followed by an examination of the experiment to find whether it's specific to a given subject(s). If the latter cannot be shown then the entire experiment can be ruled invalid. In one particular experiment, a listener was reliably identifying two particular codecs out of six (he was able to do this for every one of the music samples being listened to). This was very strange because these were among the best codecs being compared, and he never identified the one which sounded just awful to everybody else! It turned out that this listener was picking out the two codecs based on a difference in time alignment of about 25 milliseconds. Needless to say, such a result would invalidate an experiment. Well that was my point and it's gratifying that you take the time to examine this form of bias. What I'm saying here in a roundabout way is that certain results raise red flags, and usually there's a sensible explanation for what's going on. A listener downrating the reference doesn't happen too often, but it does, and I can't say that I'm all too surprised that some people will do this, especially if they're relative novices at performing this type of comparison. Unless somebody can come up with a better explanation, I chalk it up to people thinking they hear a difference when they really don't. Sure, that's a common human trait. But if they do this reliably then you need to examine further for some form of bias. As I said earlier if you cannot determine that results were limited to a given subject(s) then the whole experiment must be considered suspect. At the very least it should be repeated. One option is to ask the individual in question to repeat his test, and I suppose this could be done for future comparisons. However, I'm a very practical person. Pointing out a specific bias is one thing; pointing out vague concerns about a possible bias with no plausible mechanism in mind is another. Yes, some people could be downrating the reference because of some as of yet unguessed reason. But I think it's far more likely that they're hearing a difference that just isn't there. Darryl Miyaguchi People hear non-extant differences of human nature. That's one of the ideas behind statistical analysis. However, if they are reliably making these choices then some form of non-sonic bias has to exist. |
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I said
The copy you sent me of "The great Chicago Cable Caper" doesn't really address the issue of the audibility of amplifiers. I mistakenly identified "can you trust your Ears" with "To tweak or not to Tweak". "Can you trust your ears contains no raw data. Tom said Sure it does. You seem to want a subject by subject table. Why? It's all enumerative data about Prefer A, Prefer B or No or Preference. I understand your need to reject the data that subjects will gladly express a Preference for one of two identical sound alternatives 3/4 of the time. Live with that. I just reviewed it again and found absolutely no raw data. in fact I found no data at all. It does say the following "There wereno records kept" which looks like the truth. Is my copy incomplete? Tom said None of the raw data suggests that. I said Sure it does unless you consider a 94% probaility that a difference was heard to to suggest that no difference was heard. Tom said That's the typical amp-difference response. Sift through the data and select individual parts that seem to support one's position EVEN when they don't. Funny, it wasn't my response in general it was simply my response if you insist that the data be considered conclusive. I don't consider it conclusive and I don't think it proved that soem or one individual could hear a difference. I certainly don't think it proved the opposite. Tom said How about the below 50% data? You gonna overlook that? You can't have it both ways. No I didn't overlook that. I don't want to have it both ways. that is why i find the results inconclusive along with a few other reasons that i have already stated. Tom said At most, such examination (I do it too) might suggest further experimentation but it doesn't 'suggest' that some amplifiers were heard. Which is pretty much what I said. But, as I said, if you are to insist that the data is conclusive one would have to conclude the Counterpoint and the NAD sounded different and that there is a reasonable possibilty that one of the listeners was reliably hearing differences. The data certainly suggests that the Counterpoint and the NAD sounded different with 94% confidence. While the evidence suggests this it certainly doesn't prove it. But you said that no tests *suggest* this. Given one of the two articles that had raw data did suggest the very thing you say it does not I would be more curious to see the raw data on the 3 dozen or so other tests you have mentioned rather than see anyone's analysis of them. Aside from the statistical analysis which saves me a lot of work that I find difficult. |
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It can be argued that the midfi audio market wouldn't exist if everybody
believed that all amps sounded different and only the really high priced amps sounded good. I think it would be a weak argument. there is no debate that speakers sound the same yet, many midfi inexpensive speakers are chosen over more expensive speakers that sound better to most listeners. Many people who believe that amps sound idfferent opt for less expensive amps. Economics are a factor even in a world where everyone believes everything sounds different and the more expensive stuff is believed to be intrinsically superior. |
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(Nousaine) wrote:
Well that's the idea behind double blind testing; keep the subject and experimentor from contaminating the results. But you're being unresponsive. Why hasn't some manufacturer, seller, enthusiast produced a single relicable experiment verifying amp or wire sound? You can reject my opinion, data and experiments and you're still left with no positive data from the producer side of the fence. Why is that? Ok, I'll bite. Here's why I think there is very little positive 'scientific evidence' showing components sound different. 1. No one cares about 'proof' except the few who personally believe and want to 'prove' there are NO audible differences. 2. Those who believe there are audible differences are happy to trust their personal perceptions, regardless of the loud protestations of the few (mostly here on RAHE) that their perceptions are misguided. 3. DBTs are the preferred method of the 'debunkers' and they usually show null results because of the way the tests are conducted and the fact that all of the results are averaged. DBTs do not duplicate the way audiophiles ordinarily listen to music and compare components. (Please spare me the arguements that DBTs only change the use of sight - they are also unnatural because they require the listener to make a blind guess.) 4. Failing a DBT has not convinced very many people that "there are no differences", just that they were not able to identify the differences they normally hear under those specific DBT conditions. So why haven't those folks suggested or designed a test that would show the differences? I refer you back to No.1. above. It's an endless loop just like the DBT debates here on RAHE! Regards, Mike |
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(ludovic mirabel) wrote
The topic is: "Does ABX work for comparing high-end components?" (Bob Marcus) wrote: Yes. It works because it's a test of *hearing*, and anyone who understands how our hearing works (which ought to include any medical professional, but perhaps I'm being presumptuous here) knows that our hearing works independent of the *kind* of device making the sound we are hearing. If you know different, please tell us. It never ceases to amaze me how obviously intelligent people (perhaps I'm being presumptious here) can take such a simplistic position on this topic. If you think a well-designed DBT comparing audio components using music is just a "hearing test", then it's no wonder these debates go on and on the way they do. Regards, Mike |
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(Bob Marcus) wrote in message ...
(ludovic mirabel) wrote in message news:C7kOa.128448$R73.15582@sccrnsc04... (Dick Pierce) wrote in message et... (ludovic mirabel) wrote in message news:n7IKa.24750$Bg.13287@rwcrnsc54... The topic is: "Does ABX work for comparing high-end components?" Yes. It works because it's a test of *hearing*, and anyone who understands how our hearing works (which ought to include any medical professional, but perhaps I'm being presumptuous here) knows that our hearing works independent of the *kind* of device making the sound we are hearing. If you know different, please tell us. bob "WE" have made an important contribution to psychometrics, understanding of philosophy, acoustics etc. "WE" are not "presumptuous" one little bit. It just is not in our nature. Either "we" make sense or "we" don't. "ABX is a test of "hearing" and "Hearing works independent(ly) of the "kind" of device making the sound..." A few carping ABXers may object that a "test of hearing" has been known and practiced for years under the humble name of "hearing test" and that their beloved ABX involves also BRAIN functions we know little about; like for instance a cortical centre for MUSIC processing. Others might say that a defence lawyer produces "sounds" and is followed by a prosecutor doing the same. The juries and the judge then compare the respective sounds for difference/preference and if they find none the defendant walks Language- what's that? Ludovic Mirabel |
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