Flushing Out Myths in Consumer Audio

[Nick250]

.....more crawfishin'.....

Evening Mule. I am not getting the "crawfishin'" metaphor.

Nick

 

[MDS]

.....man alive, talk about crawfishin'....Mtry, you've said about forty times all modern amps are transparent and therefore sound the same....and, OF COURSE, you quoted some guy in a review every time....why are things different today?.....

Just an observation Mule about how things are different today. You replaced your McIntosh amps with Crown and raved about how wonderful the Crown amps are. I think you even offered to buy them for anyone that would you take you up on your offer to prove that they don't sound good given how cheap they are compared to the 'high-end' esoteric amps like McIntosh.

Fast forward to today and the same old boring 'all amps sound the same' thread with all the same arguments. NOW...you are back to using the McIntosh amps and extolling their virtues. So you thought the cheap Crown amps were a match for the McIntosh but decided to put the Mc's back in rotation and now Voila! the Mc's are the best sounding amps ever and the Crown no longer cuts the mustard.

Could it be that your ears got used to the sound of the Crown and then when you switched back you felt there was a difference? Hmmm... no chance of that...you don't believe that the human auditory system is easily fooled.

Not picking on you Mule, but you are steadfast in your beliefs and I am the type that easily remembers when someone later changes their tune to something inconsistent with their prior statements.

 

[highfihoney]

consumers do not generally do blind comparisons

sorry for the multiple reply's but i have not mastered the ability to do multiple quotes,so sue me


Are you serious? i have never saw a demo system set up at any electronics store with two different amplifiers in order for the customer to do direct AB comparisons,once again the consumer is going by memory & i'd call that as blind a test as one could get.

whats a bit odd to me is that AB testing is the accepted method for testing different speaker systems when deciding on which speaker sounds best but not with amplifiers or any other peice of gear,only the dbt method is accepted.

 

[Sleestack]

Not picking on you Mule, but you are steadfast in your beliefs and I am the type that easily remembers when someone later changes their tune to something inconsistent with their prior statements.

People being "steadfast in beliefs," is exactly the source of the problems I see on this site. While the "objectivists" might ultimately be right on many matters, each thread degenerates into broad lectures on audio principles rather than discussion about the actual pieces at hand. Not only that, but the "objectivists" often come in with a condescending tone armed with nothing but assumptions and principles. It ends up creating fruitless debate rather than meaningful discourse... and, unfortunately, it happens in almost every thread. Unless people have actual experience with the equipment at hand (or at least know some key technical specifications), I don't really see the point in interjecting and applying generalizations. They may be true, or they may not be. At the very least, specific reasons and examples for why the specific equipment falls within a generalization should be given. Otherwise, it is nothing more than repeating mantras and another form of trolling.

 

[mulester7]

Just an observation Mule about how things are different today. You replaced your McIntosh amps with Crown and raved about how wonderful the Crown amps are. I think you even offered to buy them for anyone that would you take you up on your offer to prove that they don't sound good given how cheap they are compared to the 'high-end' esoteric amps like McIntosh.

Fast forward to today and the same old boring 'all amps sound the same' thread with all the same arguments. NOW...you are back to using the McIntosh amps and extolling their virtues. So you thought the cheap Crown amps were a match for the McIntosh but decided to put the Mc's back in rotation and now Voila! the Mc's are the best sounding amps ever and the Crown no longer cuts the mustard.

Could it be that your ears got used to the sound of the Crown and then when you switched back you felt there was a difference? Hmmm... no chance of that...you don't believe that the human auditory system is easily fooled.

Not picking on you Mule, but you are steadfast in your beliefs and I am the type that easily remembers when someone later changes their tune to something inconsistent with their prior statements.

.....MDS, I plead guilty, but what made the Crowns sound that good to me was how clean they were, and I wasn't thinking presence or imaging at the time....I had a Mac amp on the surrounds and a Crown on the fronts....I walked back and forth and found the Mac sound to be a thicker sound, and went with more K2's that I'm now going to have to try to get rid of....then, I got the Earthquake because of the reviews and stated specs....it had a different sound right off the bat, but I had to get used to it's sound quality also, to be able to appreciate the presence and imaging of Mac....since going back to McIntosh on my journey of mainly the highs, I've tried the Crowns AND the Earthquake again, more than once, to make sure, and it was in fact the highs that wore me down just like before....the Crowns don't even begin to image as well as McIntosh, either....maybe my speakers figure into the mix against the Earthquake, I suspect that's so, but as for me and mine, it will be McIntosh from here on....I don't blame you for bringing this up, I'm amazed it took this long, and I appreciate your candor and honesty....oh, it wasn't the K2's I offered to buy from someone who didn't want to keep it....crap, they're 1500 bucks, haha....

 

[MDS]

Unless people have actual experience with the equipment at hand (or at least know some key technical specifications), I don't really see the point in interjecting and applying generalizations.

That is the key reason that the endless debate continues on...

The 'subjectivists' cite 'actual experience with the equipment' but refuse to concede that maybe, just possibly, their sighted evaluations of the actual equipment are not conclusive. You see it time and time again too where said subjectivists agree to a double blind test, pick the equipment, define the parameters of the test and then .... fail the test and then claim that the test was invalid. It's hypocrisy at it's finest.

Buy what you want for whatever reason....

 

[mulester7]

Unless people have actual experience with the equipment at hand, I don't really see the point in interjecting and applying generalizations.

.....total agreement, Sleestack....but even with actual experience, the speakers owned and used can emit different imaging and sound qualities....room damping can enter in also....it might be a good idea when a comment is made on the sound quality of an amp or pre-amp, that the type and brand of speakers used be stated, I don't know....I think nothing beats an inhome listening experience of components being considered.....

 

[Sleestack]

That is the key reason that the endless debate continues on...

The 'subjectivists' cite 'actual experience with the equipment' but refuse to concede that maybe, just possibly, their sighted evaluations of the actual equipment are not conclusive. You see it time and time again too where said subjectivists agree to a double blind test, pick the equipment, define the parameters of the test and then .... fail the test and then claim that the test was invalid. It's hypocrisy at it's finest.

Buy what you want for whatever reason....

Actually, I don't see many DBTs going on in this forum. I do see "subjectivists" saying that they hear differences and don't really want to subject all of their beliefs to DBT. I also see subjectivists arguing against the effectiveness of DBTs. Nevertheless, none of that happens unless there is an attack on their beliefs first. All I'm saying is if you (not meaning you specifically) are going to attack someone's conclusions, do so with specific facts or experiences, rather than generalizations that may or may not be true when applying it to the specific case at hand.

 

[AdrianMills]

I did read the links & what you think is irrelevant is not how a discussion of different veiws takes place between two grown men.

OK, I'll give you the benefit of the doubt on that one but I'm a little amused that you think a debate between "grown men" should be any different.

Ive had this discussion before in previous threads but since we have not discussed this i'll explain MY VEIWS.

DBT & level matched testing,i find it amazing that people accept this kind of memory related testing as the holy grail of audio,would you or anybody else for that matter rely on a dbt or all levels matched type of test before buying a new television ?

Our visual memory is way different from our aural memory which sort of makes a DBT of TV's a little different. It’s also real easy to compare them side by side.

Here is what i find to be the most misleading out of the whole methodology that you & many others use as a basis to form your conclusion that all amps sound the same,in a level matched dbt i agree that all amps would sound close enough that our memory isnt sufficient to tell the differences but in the consumer world this isnt applicable,the only level that should be matched for a comparison between two different amps is wattage because that is the only level that the average consumer has the ability to change & then testing should be instantainous with A B switching between the two amps.

Well, ABX and AB testing with a switch is as "instantaneous” as you can get so I don't know what issues you have with those.

Yes i have done this type of testing many times over,ive matched exact wattages with two seperate amplifiers,recorded the different sonics of each amp on gear that has the ability to save & record a visual of what levels were reached with each amp & ive also done exact wattage comparisons between different amplifiers with instantainous A B switching between the two,my conclusions from my own experience's using gear the way most consumers will use gear is that there are clear & defined differences between amplifiers & preamplifiers.

What you call a properly run test to me is nothing more than misleading information because it does not reflect real world applications of the useage of the amplifiers.

Please do tell more on these techniques you have that blow away all the other blind testing I've heard about.

I've just a little more or the thread and I see you've already answered Krabapple.

This "visual metering" - this is the power meters on the McIntosh amps right? And what do you use to set the levels on the amps you're comparing against?

However, I'm not really sure how to discuss this further with you when you're convinced that sighted tests are valid for amplifiers and you're ignoring all the research indicating that perception bias is introduced during sighted listening.

BTW, ideally speakers would be auditioned blind but it's not as essential as speakers have proven time and again to sound entirely different. One interesting thing that I heard (I've lost the link) is that sighted listening of speakers can introduce bias and, in general, when blinded, people tend to choose speakers with the flattest frequency response (as opposed to the prettiest veneer or coolest curves).

 

[krabapple]

Where exactly would the rules for burdens of proof be written for the"courts of science?" Not trying to be argumentative here, but when someone comes out and says "My amp A sounds different than amp B," and someone comes along to say, "No, they sound the same, " without any direct evidence or study of those specific amps, it would seem to me that there is no established priority for the first person to prove the differences. The second person could have very easily come along and said "those amps sound the same," with the second person responding in the negative.

Geneally the person who claims the *existence* of a phenomenon, is the one bearing the burden of proof.

I understand that even you acknowledge that some amps sound different. Nevertheless, the broad generalizations made here without actually knowing the technical specifications of each amp really don't warrant any more credibility than the statements being made about amps sounding different.

Even without knowing the specs of the amps, what is not really in doubt at this late date is the existence and power of perceptual bias. On that basis alone it is reasonable to question the accuracy of any 'conclusion' reached from sighted comparison, in the absence of other data.

That is, even objectivists should rely on direct evidence rather than broad generalizations. It is one thing to look at specifications and use them to draw the conclusion, but all too often here, I see dogmatic assumptions and conclusions being reached for the purpose of pushing an agenda rather than actually studying the specific facts invloved.

It is not 'dogmatic' to ask that 'conclusions' of audible difference take perceptual bias into account. Certainly if the 'claimant' offers *nothing* more by way of evidence than 'i listened to these two amps and they sounded different', a conclusion of difference is unwarranted. If the claimants offered *specific facts* -- which is to say, quantitative data about the amps' performance -- that would be a marvellous way for them to independently support theur claim...but how often have they done that? In their absence, are we to assume that amps TEND TO measure so differerently that we should assume that an audible difference report is as likely to be true, as false? No. Unfortunately, the opposite tends to be the case: measurable differences between modern solid state amps tend to be beyond the range of audible. Given that, plus the ubiquity of perceptual biases, what is the more reasonable conclusion?

 

[krabapple]

By using watt meters that are as accurate as any lab grade metering system & setting the amplifiers power range to an exact match.

DBT'S are not a usefull tool for me to use,a dbt requires the use of human memory which by nature makes any test results null & void,i use A B testing only & look for visual/audible differences,my goal is not to be able to pick which amp was playing my goal is to be able to pinpoint differences in the signal being sent to the speakers with hearing & visual confirmation of the differences.




I do several different types of audible/visual monitoring,first being to set up both amplifiers into the same preamp with wattage levels matched then to monitor & save the signal from each amp on its own spectrum analizer with both analizers being fed from the same mic in a central location,all circumstances stay the same for both amplifiers & A B switching is done,the monitoring is being directed at the sound comming from the speakers, after the test is done its easy to see that each different amplifier will have different levels they reach in all the freqs that are being monitored & displayed,these settings are saved & compared against each other.

The second type of testing i do is very close to the first but with a few exceptions,both amps are monitored direct from the signal being fed to the amps & with no speakers hooked up,in both cases visual differences are easily seen.

Out of curiousity how have you measured different amplifiers & translated the results into predictions of no audible difference?

Matching levels at three frequencies to within 0.2 dB at the speaker terminals, for each channel. or use an ABX comparator, which performs a similar operation audtomatically. Your 'watt matching' protocol could achieve something similar as long as you are measuring speaker terminal output, but it wold be important to know how it translates to actual output level differences (in dBs) -- because as i'm sure you know, even a difference as small a 0.5 dB in level, in the most sensitive range of hearing, can lead to a call of 'difference' when all that 'different' is the setting on the volume knob. And of cousre you want to be comparing the amps within their non-distorting ranges.

But that's a secondary issue in your case. Your eschewing of blind controls for audibility simply invalidates your results from a scientific POV, unless you can demonstrate intrinsic measureable differences in ranges that can be expcted to be audible - eg. one amp acts as an equalizer by boosting or lowering some frequencies, compared tothe other . (I would call that amp 'broken', btw)

 

[Tomorrow]

A lot of pallaver has gone on within this forum about Double Blind Tests. More than a few here still don't really know what is required in the development of a thorough, repeatable DBT. Further, I'd guess that most of you arguing the subject have never designed one, been involved with running one, been a subject in one, or can even tell me off the top of your heads a reference to one that has, using peer-review discussion and publication, distinguished between human (in)ability to identify different amps and there being NO difference between the auditory experience of a selection of amps...two very different results. I see a lot of mixing of these quite separate ideas.

Someone...anyone (Chris, maybe)...prove me wrong. Edit: Please,

 

[krabapple]

sorry for the multiple reply's but i have not mastered the ability to do multiple quotes,so sue me


Are you serious? i have never saw a demo system set up at any electronics store with two different amplifiers in order for the customer to do direct AB comparisons,once again the consumer is going by memory & i'd call that as blind a test as one could get.

Are you seriously claiming that systems tend to be demo'd *blind*?
Do you understand what 'blind' means in this context? It means that while the customer may know the names of the two amps being compared, she does not know, at any given moment , which of the two is in the circuit --*EXCEPT* by means of listening. Visual or verbal cues from the dealer
invalidate the 'blindness'. And , too a fair test requires careful level matching...do you seriously claim that THAT is the norm in demos?

whats a bit odd to me is that AB testing is the accepted method for testing different speaker systems when deciding on which speaker sounds best but not with amplifiers or any other peice of gear,only the dbt method is accepted.

Accepted by *whom*? Speakers *really do* tend to sound different, as one can predict from measurements and acoustic principles, so there, the point of blind controls is not to establish audible difference (which tends to be trivial to do), but to make sure that *preference* is really based on sound, not looks, price, brand, etc. And indeed, *double* blind tests are the gold standard there...whenever the most accurate picture of the basis of *audible preferece* is required. It is in practive much harder to set up a fair DBT of speakers than amps, though. Harman/JBL spent a million or so building a facility for just that purpose.

 

[krabapple]

A lot of pallaver has gone on within this forum about Double Blind Tests. More than a few here still don't really know what is required in the development of a thorough, repeatable DBT. Further, I'd guess that most of you arguing the subject have never designed one, been involved with running one, been a subject in one, or can even tell me off the top of your heads a reference to one that has, using peer-review discussion and publication, distinguished between human (in)ability to identify different amps and there being NO difference between the auditory experience of a selection of amps...two very different results.

Someone...anyone (Chris, maybe)...prove me wrong.

I can't come up with any proving that unicorns don't exist either...why *is* that?

Seriously, this is a red herring. Who is going to do such tests? Toole and Olive of Harman/JBL have gone to great lengths to use DBTs for speaker preference studies , and have produced peer-reviewed p\papers about it, because it's pretty much a given that loudspeakers really sound different. Isnt' it curious taht amp mfrs seem never to have let their engineers publish
such tests for amps? If amps sound different as a rule, then surely preference becomes an issue, and surely it an be analyzed as for speakers. And if they don't do it , who will? Will the NSA or NIH funds studies of amp difference, even though measurable diference between parameters of amps tend to be below thresholds of audibility?

You may of course find yourself an ABX comparator box and perform the tests yourself.


The 'identifying amps' versus 'auditory experience' is another red herring. Ifyouare convinced that it's an issue, again, you'll have to explain why sighted listening works, but an ABX test, performed *after* sighted listening has imparted the experience of difference to the listener, somehow doesn't.

 

[krabapple]

That is the key reason that the endless debate continues on...

The 'subjectivists' cite 'actual experience with the equipment' but refuse to concede that maybe, just possibly, their sighted evaluations of the actual equipment are not conclusive. You see it time and time again too where said subjectivists agree to a double blind test, pick the equipment, define the parameters of the test and then .... fail the test and then claim that the test was invalid. It's hypocrisy at it's finest.

Buy what you want for whatever reason....

Among the many interesting findings of experimental psychology, is that people tend to vastly overrate the accuracy of their own sense perceptions, memory,and 'fairness' or 'logic' of their judgement. in that light, much of audiopile culture is explained...

 

[Tomorrow]

You may of course find yourself an ABX comparator box and perform the tests yourself.


The 'identifying amps' versus 'auditory experience' is another red herring. Ifyouare convinced that it's an issue, again, you'll have to explain why sighted listening works, but an ABX test, performed *after* sighted listening has imparted the experience of difference to the listener, somehow doesn't.

We sure are grateful to have you around, Krabapple. What would we do without you? Hmmm?

As usual, you have misrepresented what I said. (I realize some concepts are difficult to comprehend, but this sounds like merely more of your impudent ego at work...just spoiling for a fight.)

My point was...clear English now...that these two disparate concepts have been argued on different threads in this forum...as though they are the same thing...which of course they are not.

 

[highfihoney]

Matching levels at three frequencies to within 0.2 dB at the speaker terminals, for each channel.

Hmmmmm,where can we buy these type amplifiers that have the ability to be adjusted at three frequencies to within 0.2 db,does such an amplifier even exist?

This is exactly why the only real usefull measurement is wattage,to my knowledge there is not nor has there ever been amplifiers where the consumer has the ability to set frequencies within the amplifier,By using testing methods like all levels matched testing the test is nothing more than forcing each amplifier to sound the same.

How can this form of testing be accurate when the testing conditions are rigged to show the same results right from the start?

 

[highfihoney]

It is in practive much harder to set up a fair DBT of speakers than amps, though. Harman/JBL spent a million or so building a facility for just that purpose.

It's impossible to set up a fair dbt where the conditions used for testing are able to be replicated constantly by the consumer,so where does all the dbt's leave the consumer after all the smoke clears & all levels go back to factory settings? with two amps that sound different.

 

[krabapple]

Hmmmmm,where can we buy these type amplifiers that have the ability to be adjusted at three frequencies to within 0.2 db,does such an amplifier even exist?

If they aren't matched, then you already know that something's wrong.
(More commonly, matching at one frequency, e,.g 1 kHz, is used before proceeding.)

This is exactly why the only real usefull measurement is wattage,to my knowledge there is not nor has there ever been amplifiers where the consumer has the ability to set frequencies within the amplifier,By using testing methods like all levels matched testing the test is nothing more than forcing each amplifier to sound the same.

You misunderstand. But tell me, why *shouldn't* two amps match at all three frequencies, when they are matched at one? Doesn't that mean at least one of the amps is acting as an equalizer? Is that what amps are designed to be? Or are they designed to be more or less 'flat' from 20-20kHz?

How can this form of testing be accurate when the testing conditions are rigged to show the same results right from the start?

Again, how is it 'rigging' to test whether one amp is potentially 'broken' ?

As I said, the common practice is to match at one frequency. If you want to be thorough, test for match at three. Because if you match at one, and the listener passes an ABX, you can be almost sure there will be a level mismatch of 0.5 dB or more somewhere in the audible spectrum.

This is not rocket science.

 

[krabapple]

It's impossible to set up a fair dbt where the conditions used for testing are able to be replicated constantly by the consumer, so where does all the dbt's leave the consumer after all the smoke clears & all levels go back to factory settings? with two amps that sound different.

By this logic, magazine reviews as written are equally useless. So are auditions in store. For that matter, so are auditions at home, unless you can 'replicate' the conditions every time. Do you agree?

Do you think that consumers should ignore results of medical trials, too? After all, they're not likely to replicate those at home either.