The “Sound” of receivers…

[unregistered]

I am troubled by the assertions - common to this forum, that double blind testing has proven the inaudibility of differences among amplifiers.

I find it credulous that folks feel that something as etherial and subjective as audibility and perception can be considered scientifically known and proved - especially given the limited set of attributes usually tested (THD, IMD, ...

Given these problems, it's more than credulous, it's fatuous to invoke science to dismiss arguements for the audibility of differences among amplifiers as Rip Van Woofer did:.

Mr. Van Woofer misses the point. It isn't that, by declaring the audibility of amplifiers, we reject the scientific method. ... Science has historically embraced many incorrect conclusions over the years, from phlogiston to the lumiferous aether. The fact that a current theory has some science to back it up isn't worthless - but it's only worth the quality of the science that it's based on. .

...The problem with the current methods of double blind testing (other than the lack of standards or consistency) is that they take music listening out of context. ....
...
Science hasn't proven the inaudibility of differences between amplifiers. In fact, it has hardly been brought to bear on the issue.

I totally agree with you there, NewYorkJosh. A lot of so-called pundits here not only misses the point, but entirely misses the hobby. We are in a hobby for self-indulgent aural gratification. It is a personal experiential indulgence. It is not a Science. DBT has no place in it.

Being a non-practicing engineer, I can very well appreciate what science can do. But it has its limits. And its place in this hobby is confined only to the manufacturing processes that make the gears we use in it. Beyond that, the hobby assumes all the dimensions of ART.

These pundits conviniently forget that the center of the hobby is NOT the gears we use, but the human people who love the sounds of music, complete with all their biases and values that bear on their choices and how they extract gratification in this hobby.

What is so admireable about scientists is that on the one hand, they have an OPEN mind that welcomes new ideas and possibilities well beyond accepted theories of the time. On the other hand, such openness is tempered by SKEPTICSM that rightly challenges such ideas. But SKEPTICSM is NOT the same as BIGOTRY and INTOLERANCE. At no time do enlightened scientists claim their explanatons to be the TRUTH. What they adhere to is a body of KNOWLEDGE - a body of facts that can evolve over time, change or even be discarded and superceded by new discoveries.

If these scientist had the same myopia, bigotry and intolerance as some so-called pundits in this forum have, there'd be nothing smaller than a proton. No blackholes. New discoveries that overturn old cherished theories are impossible for such people who embrace the results of a mere DBT as FACTS and the sole truth at the exclusion of other possibilities science need not have to prove.

Audio pundits in this forum claim statistical DBT results as a fact, the TRUTH. With the unmistakable implication that those who do not subsribe to such results are merely delusional. (That sounds so much like those protagonists during the crusades, doesn't it. Only their religion is the truth, not that of Allah or Confucius.) Now i really don't know where these so-called pundits got their impression that a DBT result is scientific fact. A DBT does use a scientific method for statistically getting the probability of an occurence with some degree of confidence. The results of a DBT, or any statisical exercise, is just that - a PROBABILITY. Embracing its results as a scientific fact, much less the TRUTH, is as much a delusion as anything you can come up with.

So if an forum member honestly opines his preferrence for this or that amp because his personal experience revealed to him that it sounded better, or that his new exotic cable suddenly opened up sounds he has not heard before, these creatures aping as audio pundits would swoop down on the hapless member to thrash and lampoon him with: "Do you have any DBT results to back-up your claims? Don't you know that DBTs from such renowned organizations as the AES, CES, ek ek, cannot discern any audible difference between a cheap amp and a multi$$$ amp? What makes you think your personal experience is reliable?" In short, if you have mere personal experiences, shut up.

I really love to rain down on their parade. I wonder if such creatures can hear themselves. This is nothing short of the bigotorus intolerance that has plagued religious wars in the past. What is so laughable is that they would do so armed merely with the STATISTICAL PROBABILITIES of a DBT. DBT results are not even a fact. It's just a PROBABILITY. No different from your exit poll. Or a market survey. When they polled the public with a sampling methodology that merely assigned a confidence of 95% that Gore would win the election of 2000, is that a FACT? But here they go trumpeting DBT results not only as a FACT, but the TRUTH!!! Nothing is more delusional than this.

This is a HOBBY that can accommodate as many VALUE perceptions as there are persons on earth. And the market is more than willing to cater to such diversity. No one is forcing anyone to get a product if his VALUE perception cannot square with the claims of that product. But their VALUE is just as VALID as anyone who does. There can be no right or wrong. What's the point of having a right and a wrong in a hobby that is only good for the person indulging in it? What one enjoys in this hobby is his concern, not anybody's. What relevance does DBT have in this hobby? NONE. It cannot and does not increase your enjoyment in the pursuit of high fidelity. Worse, by saying that all amps and cables sound the same, you effectively close options beyond a $300 receiver and a coat hangar. My goodness. You might as well question why I bought a Lexus instead of a BMW. A DBT probably will tell you that all luxury cars feel the same. But nobody buys a car, or any luxury item using DBT. Carried to an extreme analogy, they might as well question you why you married your spouse. A DBT will probably tell you that all cunts and penises across the continent feel the same. And I wouldn't be surprised if these creatures who espouse DBT also choose their spouse using DBT.

This hobby is an indulgence of the human appetite for feasting on musical sounds. It is not a science. This hobby is not a SCIENTIFIC exploration nor a pusuit where you must adhere to scientific methods in order to enjoy its fruits. THere was a time in the past when royalties, the aristocrats and the noveau rich indulged those appetites by inviting chamber musicians to play in their palatial homes all night or all weekend. They even commission musicians to compose for special occasions and to play them in their homes. If I can afford to invite Claudio Abbado and the CHicago Symphony Orchestra to play every night at home, why not? But with the pressures of work and other commitments, plus the logistical and financial nightmares that attend such frivolity, audiophiles have come to compromise their indulgences and settle with some TECHNICAL audio gears that allow them to appreciate their favourite music with the degree of fidelity available at the time and which they belive can be had only with the most expensive equipment. It's very convenient, allowing them to engage in their appetites anytime. Now just because these audio gears were made by engineering processes made possible by the sciences doesn't mean they have to adhere to sceintific methods in indulging their senses. And just because they would rather spend on a $15,000 Mark Levinson or a $1,000 per meter cable doesn't mean they're dellusional. To say so would not only be the height of envy and stupidity, but assumes dictatorial proclivities that have no place in this hobby, or anywhere else

AV_PHILE

 

[Unregistered]

Finally, audio engineering as a profession, and the AES as an organization, do not exist in a vacuum. There is the other electrical engineering organization, the IEEE. There are the various scientific and engineering disciplines and their attendant professional organizations that deal with hearing, perception, psychology (same thing?) and acoustics -- all of which have an obvious bearing on audio and some of whose members certainly have some professional interest in sound reproduction. Indeed, audio engineering itself is a very "multi-disciplinary" profession; its practitioners (hence also many AES members) are also physisicts, mathemeticians, acousticians, even musicians (so much for the "soulless lab geek" stereotype). Is there evidence or any breakthroughs in understanding from any of those disciplines to support the hypothesis that a Sony from Best Buy sounds different from a Krell? Hasn't some psychologist (say) doing cutting-edge research into human hearing and perception met his buddy the electrical engineer at an AES convention and said, "Hey, Joe, I've found something out that suggests people really can hear the difference after all." -- let alone presented a paper that survived peer review?

BTW, ears are splendid things. Music woudn't be possible without 'em. But for best results they need to be connected to your brain.

Audio is science and engineering. Music is art. And listening and appreciating music is an ART as well. Audio is just another component of this HOBBY. Let's not confuse a mere part with the totality of the hobby.

And yes, every ear is and should be connected to the brain. And every thinking brain has a unique personality of its own - complete with biases, values, preferrences, experiences, whims, dislikes - some of the things that comprise humanity. All these bear down on a person's perceptions that are used to make the hobby as enjoyable as possible to the hobbyst. Anything that doesn't add to that enjoyment is irrelevant to the hobby.

AV_PHILE

 

[Mudcat]

That was a rather nice monolog AV_Phile. But I think that both you and NYJ are missing the key point (at least the way I see it). I get the impression that you think that most of us think that DBT is the end all and be all for every experience, no matter how uncontrolled it may be. That is not the case. Most of us probably believe that the merits of DBT do not have a value under random circumstances. It is that randomness that needs to be removed from a situation before the value of a DBT can be considered. Almost everything those debunking DBT have focused on involve too many random variables, you say this amp sound better than that amp over there. But this amp is here and that amp is there. We are not telling you that you did not hear differences in the amps, we are telling you that what you think you heard may not have been actual differences in the amps, but differences in the environment (even if they were in the same room). All it would take is one little tweak of a knob here, a little higher on that fader there, etc.

Mtrycrafts often misses the point too, he thinks everything should be DBT'd.

Personally, I do not think that amps and receivers can be effectively DBT'd, too many variables to control. But, do not ever tell me you heard differences in cables.

Oh yeah, the put down of bigotry from you was a bit funny. Especially considering how, according to you, anything from the orient is isn't worth it's components. Open up your Rotel and tell me what is says on the circuit boards. Most likely "Made in Malayasia" or "Made in Singapore".

 

[Rip Van Woofer]

Audio is science and engineering. Music is art.

Precicely. That is why I prefer to apply the standards of science to the former, and the standards of art to the latter.

 

[miklorsmith]

There seems to be a broader discussion at hand here. "Amplifiers" almost seem to be a euphamism for overpriced audio whatnot altogether, be it cables, preamps, whatever.

I propose a test, which I think I can conduct fairly objectively. I will pit my $6,000 electronics against my garage system, both hooked up to my main, very revealing speakers. I will play within the limits of the 35 watt garage amp. I will use my quality but not hugely priced cables with the good system and clean, basic cables with the other. I will listen DBT. I generally have no interest in spending my time this way, but I am absolutely sure I will have positive results.

I bet Mtrycrafts is with me. Any other takers?

 

[toquemon]

As far as i can tell, my system sounds much better if i seat in my beloved leather couch,with medium light, smoke one of my Montecristo's cigars and after drinking at least 4 shots of my Tequila Herradura Reposado. As you can see, only in altered conditions i can hear a difference between my amp and my same amp. This is not a joke, i truly hear differences when i'm in the state i described above. So, to those "audiophiles" who claim to hear differences, sorry, but it is only psychological.
If you attend to the facts i would say one thing: i preffer to trust in mathematical theory and engineering principles than believe in the nonsense, not founded, subjective "audiophile" claims.

 

[NewYorkJosh]

I've learned a lot on this forum. First and foremost, I've learned to read reviews and ads in the High End with a more critical eye. Once you start you bulls!@# detector running you'll start to see a LOT of BS in the high-end. I've looked through the box of audio stuff that I've bought and not used much over the years and there's a lot of tweaks that didn't make much (any) difference and ended up in storage. The ads for these products were composed of a lot of pseudo science - scientific sounding language that wasn't based on testable recognizeable ideas. A rationalist, taking these observations to their logical end, ends up questioning the audibility of all kinds of things - like the differences between amplifiers, caps, tweaks, etc... (There doesn't seem to be any debate about the audibility of difference between speakers). Viewed in the hard light of day, there are few claims of the high end that have been scientifically, verifiably, tested. Given the overwhelming flood of audiophile press and on-line content, the myths take on the glamour of fact with repetition and newbies start spouting myth as truth. The objectivists, a minority voice, can be sympathisized with for getting hot under the collar as excuse after excuse is thrown their way.

The sad fact, however, is that there really hasn't been a great deal of formally done, published, DBT either.

The rationalists repeatedly point to two specific pieces of evidence for the assertion that well designed amps within their operating parameters sound the same:
1) Richard Clark's amp challenge. While this is certainly provocative (that literally thousands of audiophiles have failed this test, and none passed) there are some problems. Foremost is the requirement that the amps be equalized to measure similarly flat (although I don't have a problem with this clause). The presence of additional circuitry in one end of the comparison has led some to say it's a competition between equalizers, or that the qualities of an amp are obscured by equalization (wouldn't that make it easier to tell the difference?). Secondarily is the hints that a subject must pass enough "preliminary tests" to be considered "serious enough" for exact sound level matching for the money round. No one passes the higher bar of the money round - and statistically the bar is high indeed, whether the full 24 rounds, or the amended 12 is the standard. Clark offers fewer rounds if the challenger puts up money - who knows how often this has been accepted? Ultimately, I don't know (and no one has yet told me) where Clark is published in a peer reviewed journal - so really Clark's claims are also anecdotal.

2) The second piece of evidence cited is the Sunshine Audio shootout (don't know when - at least before 1996) with Tom Nousaine showing audiophile Steve Zipser and his wife and couple of more audiophiles no difference between a Yamaha integrated amp and Pass Labs Aleph. Zipser (may he rest in peace) was an outspoken audiophile and, dare I say, a blowhard with a big ego cruising for a bruising. His failure to hear the differences between the amps has achieved the status of legend. I'm not going to debate the veracity of the story - but this is also fairly anecdotal evidence, also not published (except in a lot of gloating threads).

That's it! Where's the meat? On the other side of the equation there's the Audiophile magazine SBT in 1989 (http://www.stereophile.com/features/113/index.html) that shows a fairly week, but barely significant demonstration of audibility. And there's the ABX double blind comparator page whose results are fairly inconclusive (http://www.pcavtech.com/abx/index.htm). I haven't found much published evidence on either side. WinAx (Chris) convincingly argues that audiophiles have the burden of proof to prove audibility. There's no proving inaudibility - only a lack of proof on the other side. I definitely agree. I'd say the audiblity between amps is an unproven hypothesis. Both sides of the objectivist/subjectivist debate need to be careful. The shrill tones do, indeed, sound like dogma on both sides of the aisle.

As a final point, I've been doing SBT testing lately in the following system:
CD front end - Theta Data Basic2>Muse Model 2 DAC
Amp1: Yamaha 5760
Amp2: ARC SP14>ARC Classic60 with KT90 tubes
Speakers: ProAc Response 2
Honestly speaking, the difference (if any) is shockingly subtle. Given the fact that the ARC amp & pre cost over $5K and the Yamaha less than $400, the value arguement is hard pressed. I'm still testing (and figuring out a way to properly level match) but I'm getting closer to the objectivist position.

I've misplaced the link here to the published paper showing that a SET triode amp, while having higher THD than a small SS amp, had more begning distortion and that feedback created audible higher order distortion products that weren't properly measured in the THD using conventional methodology. I'll post is asap. I conclude by reinterating my belief that science will someday transform both positions.

 

[miklorsmith]

Does anybody here know why amplifiers are the chosen component here? Is it simply that no one has started the global dialog regarding the same discussion of other components?

I feel this to be a tremendously important question:

1) Other components are generally made of the same types of parts as amplifiers. Logically speaking, it is necessarily true that if amplifiers sound the same, each of the component parts inside do not audibly affect sound. If we hold this to be true, can we not expand this thinking to other components? After all, they are also made of the same basic parts as amplifiers.

2) Is it possible that the problem of DBT where a single part is swapped and the listener fails positive recognition is one of small increments? A small change may fool the listener, no?

3) I postulate that a small difference is worlds apart from no difference, because

4) Small changes, added together, can be tremendous.

This line of thought is at the root of the seemingly ridiculous test I proposed, above. I'm not an electrical engineer - is there a competent rationale for holding amplifiers to the fire, but not the rest of our systems? If we can throw everything in together, I'll do a DBT. If my garage system matches the expensive one, I'll sell all my spendy stuff on Audiogon tomorrow.

 

[Rob Babcock]

You may find it difficult to perform your DBT properly, miklorsmith. First, you'll have to match the levels very very closely, perhaps to a tolerence of 0.1 dB (even very small differences in volume will bias the results towards the louder option). This isn't possible to do by ear, and you'll need something pretty sensitive to do so. Then you'll need someone to switch the amps (or whatever you're testing) very rapidly. Audio memory is about 2 seconds, so it's important the switch be quick to give yourself the best chance to hear meaningful differences. The last and toughest requirement: the person who does the switching for you can't know what he's switching, either, or else it's not double blind. DBT insures that the switcher doesn't inadvertently communicate his/her biases to you, the listener.

Still, I'm interested to hear of your results. Good luck.

 

[mtrycrafts]

Mtrycrafts often misses the point too, he thinks everything should be DBT'd.

Not at all. On the contrary. BUT, I do try to interject it every time someone makes a testable claim based on unreliable protocols.
Today, there is no real need for it as good equipment are transparent and can be chosen by other aspects than sound.

Personally, I do not think that amps and receivers can be effectively DBT'd, too many variables to control.

Level matching, random swapping, statistical results
How can they be effectively evaluated if the sound is the criteria one uses?


Open up your Rotel and tell me what is says on the circuit boards. Most likely "Made in Malayasia" or "Made in Singapore".

LOL

 

[mtrycrafts]

There seems to be a broader discussion at hand here. "Amplifiers" almost seem to be a euphamism for overpriced audio whatnot altogether, be it cables, preamps, whatever.

I propose a test, which I think I can conduct fairly objectively. I will pit my $6,000 electronics against my garage system, both hooked up to my main, very revealing speakers. I will play within the limits of the 35 watt garage amp. I will use my quality but not hugely priced cables with the good system and clean, basic cables with the other. I will listen DBT. I generally have no interest in spending my time this way, but I am absolutely sure I will have positive results.

I bet Mtrycrafts is with me. Any other takers?

All depends on your garage system, even if you keep it within design limits. Does it have flat frequency response? Low distortion? Make sure you level match it to close tolerence level.

But, before you start:

http://groups.google.com/groups?dq=&hl=en&lr=&ie=UTF-8&oe=UTF-8&threadm=KBiic.13512$w96.1245040@attbi_s54&prev=/groups?hl=en&group=rec.audio.high-end


Also published: "To Tweak, or Not to Tweak?", Nousaine, Tom, Stereo Review, Jun 98, pg 79-81.

Probability is not on your side Unless, there is something wrong with the garage system you or we don't know about

 

[WmAx]

(http://www.stereophile.com/features/113/index.html) that shows a fairly week, but barely significant demonstration of audibility. And there's the ABX double blind comparator page whose results are fairly inconclusive

Quite a difference in frequency response between the tested amplifiers. While this would be extremely subtle, it would probably be audible in a high sensitivity ABX test session to skilled listeners. Such things should have been checked BEFORE the ABX test. From the wording of this article, it appears the frequency respone was anlaysed after the test.

-Chris

 

[mtrycrafts]

I've learned a lot on this forum. First and foremost, I've learned to read reviews and ads in the High End with a more critical eye. Once you start you bulls!@# detector running you'll start to see a LOT of BS in the high-end. I've looked through the box of audio stuff that I've bought and not used much over the years and there's a lot of tweaks that didn't make much (any) difference and ended up in storage. The ads for these products were composed of a lot of pseudo science - scientific sounding language that wasn't based on testable recognizeable ideas. A rationalist, taking these observations to their logical end, ends up questioning the audibility of all kinds of things - like the differences between amplifiers, caps, tweaks, etc... (There doesn't seem to be any debate about the audibility of difference between speakers). Viewed in the hard light of day, there are few claims of the high end that have been scientifically, verifiably, tested. Given the overwhelming flood of audiophile press and on-line content, the myths take on the glamour of fact with repetition and newbies start spouting myth as truth. The objectivists, a minority voice, can be sympathisized with for getting hot under the collar as excuse after excuse is thrown their way.

The sad fact, however, is that there really hasn't been a great deal of formally done, published, DBT either.

The rationalists repeatedly point to two specific pieces of evidence for the assertion that well designed amps within their operating parameters sound the same:
1) Richard Clark's amp challenge. While this is certainly provocative (that literally thousands of audiophiles have failed this test, and none passed) there are some problems. Foremost is the requirement that the amps be equalized to measure similarly flat (although I don't have a problem with this clause). The presence of additional circuitry in one end of the comparison has led some to say it's a competition between equalizers, or that the qualities of an amp are obscured by equalization (wouldn't that make it easier to tell the difference?). Secondarily is the hints that a subject must pass enough "preliminary tests" to be considered "serious enough" for exact sound level matching for the money round. No one passes the higher bar of the money round - and statistically the bar is high indeed, whether the full 24 rounds, or the amended 12 is the standard. Clark offers fewer rounds if the challenger puts up money - who knows how often this has been accepted? Ultimately, I don't know (and no one has yet told me) where Clark is published in a peer reviewed journal - so really Clark's claims are also anecdotal.

2) The second piece of evidence cited is the Sunshine Audio shootout (don't know when - at least before 1996) with Tom Nousaine showing audiophile Steve Zipser and his wife and couple of more audiophiles no difference between a Yamaha integrated amp and Pass Labs Aleph. Zipser (may he rest in peace) was an outspoken audiophile and, dare I say, a blowhard with a big ego cruising for a bruising. His failure to hear the differences between the amps has achieved the status of legend. I'm not going to debate the veracity of the story - but this is also fairly anecdotal evidence, also not published (except in a lot of gloating threads).

That's it! Where's the meat? On the other side of the equation there's the Audiophile magazine SBT in 1989 (http://www.stereophile.com/features/113/index.html) that shows a fairly week, but barely significant demonstration of audibility. And there's the ABX double blind comparator page whose results are fairly inconclusive (http://www.pcavtech.com/abx/index.htm). I haven't found much published evidence on either side. WinAx (Chris) convincingly argues that audiophiles have the burden of proof to prove audibility. There's no proving inaudibility - only a lack of proof on the other side. I definitely agree. I'd say the audiblity between amps is an unproven hypothesis. Both sides of the objectivist/subjectivist debate need to be careful. The shrill tones do, indeed, sound like dogma on both sides of the aisle.

As a final point, I've been doing SBT testing lately in the following system:
CD front end - Theta Data Basic2>Muse Model 2 DAC
Amp1: Yamaha 5760
Amp2: ARC SP14>ARC Classic60 with KT90 tubes
Speakers: ProAc Response 2
Honestly speaking, the difference (if any) is shockingly subtle. Given the fact that the ARC amp & pre cost over $5K and the Yamaha less than $400, the value arguement is hard pressed. I'm still testing (and figuring out a way to properly level match) but I'm getting closer to the objectivist position.

I've misplaced the link here to the published paper showing that a SET triode amp, while having higher THD than a small SS amp, had more begning distortion and that feedback created audible higher order distortion products that weren't properly measured in the THD using conventional methodology. I'll post is asap. I conclude by reinterating my belief that science will someday transform both positions.

Very good summary

To level match properly, you should use a volt meter at the speaker terminal that is capable of responding to 1kHz and 10kHz as you should at least check how closely at these frequencies match; also at 100Hz. The meter should be sensitive to be accurate to 1% of 2.83V as you would use something like that level of a test signal to level match, or, if that is too loud as it most likely would be, a voltage level that is comfortable for you to listen to.

"Topological Analysis of Consumer Audio Electronics: Another Approach to Show that MOdern Audio Electronics are Acoustically Transparent", Rich, David and Aczel, Peter, 99 AES Convention, 1995, Print #4053.


While this reference doesn't include DBT listening tests, Dr David Rich has been conducting them for a vely long time as the Technical director at The Audio Critic magazine, along with Peter Aczel, who, by the way, was a golden ear at one time.

"The Great Debate: Is Anyone Winning?", Nousaine, Tom, Proceedings of the AES, 8th International Conference, 1990.

This reference compiled 23 DBT listening amp tests up to that time, including the one you cited from Strereophile and in fact it comments on its problems brough on by Stereophile. I wasn't there, furthest from my mind at the time

I wasn't there for the Zipser test either and the link is used for easy reading. It was conducted on 25 Aug 1996, in the link, 2nd para, 2/3 line.
It was also published as a letter to editor in The Audio Critic. If I recall correctly, Steve has commented on it many times afterwards over the years. Not favorably, or fourse with many excuses
I seriously doubt Tom would put his reputation on the line for this.

I seriously doubt you will see any DBT listening on audio component published in a Journal. The best at hand are magazine published as cited above and many others on wire and CD not cited above but have in my library
We do the best with what is at hand. No interest from the component makers, etc.

I believe you are looking for the link on a publication by Glass Audio about tube distortion. THD covers total harmonic distortions, that is what it is. Doesn't exclude any.

John Dunlavy has certainly demostrated the power of placebo and cable tests, never published except on line discussions

Floyd Toole has and does today, conducted DBT on speakers and yes, bias can dictate there too and he has published Journal papers on that.

 

[Rip Van Woofer]

Tsk, tsk! You didn't mention the real "meat": David (not Richard) Clark's two AES papers on DBT (aka ABX); one of which recaps ten years(!) of testing.

"High-Resolution Subjective Testing Using a Double-Blind Comparator" Journal of the AES, Volume 30 Number 5 pp. 330-338; May 1982 Available as a reprint for $5 (AES members) or $20 (non-members)

"Ten years of A/B/X Testing" (available from AES as a "preprint" for $5. I think AES "preprints" are papers that were presented at AES conventions but did not appear in the Journal)

Summary: Experience from many years of double-blind listening tests of audio equipment is summarized. The results are generally consistent with threshold estimates from psychoacoustic literature, that is, listeners often fail to prove they can hear a difference after non-controlled listening suggested that there was one. However, the fantasy of audible differences continues despite the fact of audibility thresholds.

Preprint Number: 3167

Author: Clark, David L.

Visit the AES Website

 

[mtrycrafts]

Tsk, tsk! You didn't mention the real "meat": David (not Richard) Clark's two AES papers on DBT (aka ABX); one of which recaps ten years(!) of testing.

"High-Resolution Subjective Testing Using a Double-Blind Comparator" Journal of the AES, Volume 30 Number 5 pp. 330-338; May 1982 Available as a reprint for $5 (AES members) or $20 (non-members)

"Ten years of A/B/X Testing" (available from AES as a "preprint" for $5. I think AES "preprints" are papers that were presented at AES conventions but did not appear in the Journal)

Summary: Experience from many years of double-blind listening tests of audio equipment is summarized. The results are generally consistent with threshold estimates from psychoacoustic literature, that is, listeners often fail to prove they can hear a difference after non-controlled listening suggested that there was one. However, the fantasy of audible differences continues despite the fact of audibility thresholds.

Preprint Number: 3167

Author: Clark, David L.

Visit the AES Website

If I covered everything, you would be bored, not much to post

The 8Th International Proceedings identifies and points out problems and causes of amp tests, including statistics. Just a different publication. He should get them all for a more complete library

 

[Rip Van Woofer]

Both sides of the objectivist/subjectivist debate need to be careful. The shrill tones do, indeed, sound like dogma on both sides of the aisle.

Shrill? SHRILL!!??!! ARE YOU CALLING ME SHRILL??!!??

 

[Pat D]

Quite a difference in frequency response between the tested amplifiers. While this would be extremely subtle, it would probably be audible in a high sensitivity ABX test session to skilled listeners. Such things should have been checked BEFORE the ABX test. From the wording of this article, it appears the frequency respone was anlaysed after the test.

-Chris

Yes, one would hardly be surprised at some difference here with those levels of difference as they are greater than the JNDs shown on the ABX site. I imagine they would show up on pink noise without too much difficulty but would be more harder to hear with most music.

Of course, it seems the aim of the test was to determine whether there was an audible difference between the amplifiers without any attempt to equalize the frequency responses, not even just with tone controls as in Nousaines Tweak vs. Geek test. Of course, superaudiophile equipment often doesn't have tone controls!

 

[Unregistered]

Tsk, tsk! You didn't mention the real "meat": David (not Richard) Clark's two AES papers on DBT (aka ABX); one of which recaps ten years(!) of testing.

"High-Resolution Subjective Testing Using a Double-Blind Comparator" Journal of the AES, Volume 30 Number 5 pp. 330-338; May 1982 Available as a reprint for $5 (AES members) or $20 (non-members)

"Ten years of A/B/X Testing" (available from AES as a "preprint" for $5. I think AES "preprints" are papers that were presented at AES conventions but did not appear in the Journal)

Summary: Experience from many years of double-blind listening tests of audio equipment is summarized. The results are generally consistent with threshold estimates from psychoacoustic literature, that is, listeners often fail to prove they can hear a difference after non-controlled listening suggested that there was one. However, the fantasy of audible differences continues despite the fact of audibility thresholds.

Preprint Number: 3167

Author: Clark, David L.

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Thanks, Rip! I was hoping I would get a more comprehensive list of citiations out of my moderately inflamitory post. I'll check these out.

 

[NewYorkJosh]

Oops - forgot to log in

Thanks, Rip! I was hoping I would get a more comprehensive list of citiations out of my moderately inflamitory post. I'll check these out.

(It's NYJosh - I forgot to log in).

 

[NewYorkJosh]

Does anybody here know why amplifiers are the chosen component here? Is it simply that no one has started the global dialog regarding the same discussion of other components?

I feel this to be a tremendously important question:

Initially - I'd answer by saying that this thread is explicitly about "Receiver sound" (and I don't think they intend the tuner section). Receiver sound has a pre-amp stage too - I'm currently comparing a receiver against an amp/pre-amp pairing. The objectivists clearly acknowledge audible differences among speakers. No one would debate audible differences among turntables, or other analog gear like tape rigs. That leaves digital source components like CD/DVD. Please don't tell me that objectivists argue that CD players all sound the same! I swear, upgrading my CD transport was huge - even bigger than upgrading my DAC!