Flacs are inferior to wavs? - Page 13

Yet another example of your inability to stick to the topic, Amir.

The question that most of us are discussing, and the one that you Amir are constantly are running away from in fear is whether or not the timing is different enough to be audibly troubling, or audibly different at all.

The answer to your question Amir, as narrow, irrelevant, self-centered and badly-formed as it is, is that I have tested nearly 100 audio interfaces ranging from the sublime to the ridiculous, and found that all of them play identical data stored in different places so similarly that I could find no reliable differences that I could attribute to file location. When I played the same data in two different places the results were so similar that I could find no reliable differences.

Many of my tests were objective, that is to say performed with test equipment. The test equipment had residual distortions many orders of magnitude below any generally-agreed upon thresholds of reliable human perception.

Yes. The earth itself has experienced minor changes to its orientation and configuration since then. The force of gravity varies over the face of the earth. The distribution of material in the crust and the core of the earth has changed over the past 300 years. The net gravitational forces in the universe that act on the earth change as the earth circulates through the universe.

Just another example of how you say so much here so forcefully in an apparent state of ignorance, Amir.

The above is an example of Amir using deception to try to convey a false impression.



IMO Amir should be banned from this discussion based on his repeatedly demonstrated inability to convey the truth about what other people say here. He does this again and again and again. It appears that he does this because of some kind of mental degradation.

Amir, you gave me the same chance and when I took it, you made repeated false claims about what I said. Please show us some evidence of good faith!

Note that Amir keeps pretending that this obvious and serious exposure does not exist.

"Up-Down threshold and AB comparison listening tests were conducted to determine the threshold of
audibility for jitter-induced distortion. The threshold of audibility for pure tones was found to be about
10 ns rms at 20 kHz and higher at lower frequencies. For nearly all program material no audible
degradation was heard for any amount of jitter added below the level at which the DIR lost lock.
Certain program material was found in which an audible degradation due to jitter was heard. The
threshold of audibility for these programs was generally found to be in the range of 30 ns rms to 300 ns
rms for sinusoidal jitter. Finally, the audible degradation was found to correspond to measurable
changes in the spectrum of the program material.
The influence of jitter in causing audible distortion was found to be less than anticipated by the
authors, and less than that predicted by both the technical and consumer audio press. Jitter induced by
the digital audio interface was not found to be an audible problem for any of the program material
auditioned."
Theoretical and Audible Effects of Jitter on Digital Audio Quality
Eric Benjamin and Benjamin Gannon
Dolby Laboratories Inc.
San Francisco, CA 94103-4813, USA

Presented at the 105th Convention AES
1998 September

From "Digital Sound Signals : Subjective Effects of Jitter" BBC publication 1974-11:

"The tolerance varies from a timing jitter amplitude of 3.5 milliseconds for sinusoidal variation over a period of 50 seconds to 35 nanoseconds for jitter frequencies of 2 KHz or higher."

...And CPUs do not play files, nor do computers read files directly from hard drives. Didn't MS teach you about RAM? Maybe you were out that day.

WAV > FLAC > WAV * n. Repeat ad infinitum. Checksum. Same result? Good conversion process. Different result? Something is broken in your conversion process. If so, re-examine process, don't hastily conclude that if A = B, then later you find that B is not = A, something is afoot at the Circle K. Whoa!

No DAC is necessary. Jitter is irrelevant because it's not induced during the file conversion process. Oops. I'm lecturing you about something you already know again.


I don't know. I would have to play my files in New York and then play my files in Burbank and compare them with a mechanical stopwatch kept hermetically sealed in an envelope licked by a diseased yak.

Here's another link from J.River for interested readers that mostly reiterates Will2007 , ironically the software player chosen.
http://wiki.jriver.com/index.php/Lossless_Compression


Sorry, nothing about yaks, but I hope Will's gets better.
Disclaimer: no Yaks are harmed in the playback of digital music.

Thanks. I'm not sure exactly what's wrong with him. I think it's something about pace, rhythm, and timing. He sounds bad.


Maybe not those yaks. My yak's ears bleed when I play lossless files within earshot because my jitter filters allow timing errors of 52 ns rms at 100 kHz to get through. I really need a new $3,500+ DAC. Maybe Amir could sell me one. A DAC for a yak.

I am sorry but that test is 14 years old. According to Arny, anything that old doesn't count. I say device jitter has gotten a lot worse since then. According to Arny, the jitter injection shown in Hawksford paper is now standard in virtually all AVRs. Therefore, we cannot use any results from that listening test. Importantly according to Arny, the AES specifications have been revised in *2009* so therefore, anyone saying anything about jitter prior to that must be mistaken.

On the other hand, the listening test in question here was run just last year. I hear laws of gravity have changed so surely electrons move differently on the S/PDIF cable, easily explaining why we would hear digital artifacts now and couldn't before.




Seriously, as I repeatedly say, you *cannot* use the simple talking points from these articles this way. You have to read and fully appreciate the context of the problem at hand. Jitter is an animal that has a thousand heads and shapes. It is not one number and certainly not one component. Have you read the whole Dolby paper? If you had you see that it does not invalidate the test results we are talking about. To invalidate the test in question you would need to duplicate all of their test conditions and the Dolby paper is anything but that.

What they did was similar to the Hawksford paper in that they built a fixture to inject jitter into four DACs they built or got as bread board (i.e. not the PS Audio DAC the authors used). The fixture accepts input from a "function generator" which means only *one* jitter frequency was picked which was independent of program material. They used single frequency sine waves as the jitter contribution. This, despite the fact that they later say they measured jitter and found that it has lots of spectrum. We know this to be case from Paul Miller spectrum analysis of real audio products we buy. There are dozens of jitter frequencies even though he caps them at a low frequency (3.5 Khz?). Since each jitter frequency creates its own side bands of distortion, the results are accumulative.

The Dolby paper has really good discoveries including the fact that listeners quickly became more acute as the testing went on which is what the TAS authors claim in training themselves. Dolby also confirms what they found that some content is much more revealing than others when it comes to even this simple jitter test. So on this front, they actually back the findings of the TAS authors! And work against random Joe saying he ran a test on some random song and couldn't hear a difference. Because the set is infinite, the Dolby testers experimented and settled on single tone that they changed from song to song. For example, for one track they used 1700 Hz for another, 1530 Hz.

One of the things I don't like is that they did not let the listener change volumes. This is unusual. I hear why they did it because they had changed test conditions for each track with different jitter and wanted the results to be comparable. But it is a pretty strong handicap for a person trying to detect a distortion. When something gets quiet and I can barely hear something wrong (typical of jitter contributions), I like to be able to turn up the volume and try again. Not letting me do that means that I have that result for only that volume level and no other.

The other downer is the practice of averaging results across listeners as you quote above. We are not discussing here what everyone hears. But rather, what the select few who care about the best fidelity and spend a lot of time listening to music may be able to hear. In that sense, it is important to know the best case situation as well. Let's take the pure tone test where one dude 's detectability was 20 to 30 ns whereas another had scores ranging from 3 ns to 6 ns with average of 5 ns. That is a far cry from the other tester and it is not proper to average the two of them if we are interested in the minimum audibility level. As an interesting aside, measurements of mass market AVRs which over HDMI have jitter distortions which are at the levels that this good listener could detect in this instance.

The above is for 8 Khz tone. The next tone they tested is 20 Khz. And the one before it is 4 Khz. There is no data for other pure tones because the problem as I have been mentioning repeatedly quickly gets out of control if we consider all music tones and all jitter spectrums. The set is easily infinite.

As you see, you do have to read the paper. And if you read it, you realize it doesn't a all mimic what the TAS testers did. While the Dolby test was artificial with a single sine wave tone for jitter at specific frequencies, the TAS test let the PC sing its song of jitter however it wanted. There is every evidence to believe that the PC does not have pretty sine wave jitter components.

Take the hard disk. Every time it starts, it kicks the power supply in the knee and runs for a few millisconds to seek and fetch its data and then goes back to the quiescent state of spinning its platter. That seek current pulse is not going to be a sine wave. It is going to be an impulse, rich with harmonics. Windows has a timer that goes off in regular intervals for timing keeping and event triggering. This happens at regular cadence all the time. On every pulse, the CPU kicks the power supply in its private parts with tens of amps of peak current requirement. It then executes some code and goes back to sleep. This again is not a pretty sine wave.

Then there is the issue of data dependency. The Hawksford paper and numerous others talk about the broken architecture of digital audio interface and how it can induce jitter that is *program dependent*. This kind of distortion comes and goes with your music and can be much more audible. Imagine I play a hiss every time your bass plays (I am making this up). You will hear this more than if the hiss was constant and you got used to it. The dolby jitter was constant and independent of digital bit stream playing.

Importantly, when we are talking about a PC in this equation which Dolby people did not use (they used a very low jitter CD player), in addition to screwing with the timing of S/PDIF, it can transmit pretty strong noise and RF down the coax cable. The DAC could respond to this in many ways, including the noise just riding on its analog output, having its analog reference change, or induce additional jitter. It is impossible to model let alone simulate such highly variable characteristics.

Net, net, we cannot nullify a positive outcome from the TAS test with a negative outcome in a completely unrelated test.

The analysis in Hawksford and Dunn and interestingly enough, a bit in the Dolby paper is the right approach where we model the threshold of listening and then determine what jitter distortion can be proven to be inaudible. Since this is a mathematical proof, and we meet its criteria, we can have high confidence in what teaches us. This is where the .5 ns numbers (and those lower than it), come from. Anything higher is just a crapshot and data point but not representative of all situations or even 1% of the situations when we have a problem that exists as infinite scope.

I should note that I really like the Dolby paper and their findings. These guys know audio compression so they used that to model the psychoacoustics of jitter. I wish that was the cornerstone of their report and they had expanded on that, rather than spending most of their article talking about some sample points which we cannot show to be representative of critical listeners across broad set of material and PC sources.

Last but not least, I hope we don't turn this thread into "prove jitter is audible." We are discussing the TAS article which is not a jitter test but a system test. And I have already said that I completely disagree with their findings.

Stay with me Will as this will be a constructive path. I promise.

Everything you said above is true. Now please demonstrate that test that the TAS authors performed was that of above. After all if it is not, then your point is irrelevant. Right?

BTW, I am saddened to see that you skipped over the many posts where we covered the answer to this riddle. But I can live .

I laid a trap for you Amir by posting a quote from an even older source before you posted this mash-up. This post shows that you are incapable of remembering or understanding things you read on the same day.

Yesterday I also explained to you how our thresholds of hearing remain the same, and how equipment design and construction can change greatly. This post seems to show that you were incapable of understanding that as well.


Amir, surely not based on your incompetent memories?


Of course I said no such thing. In fact I said that jitter removal schemes are standard in virtually all AVRs, which is a completely different thing. More proof of your inability to grasp simple concepts and terminology, Amir.

Before you do, it would be great to get your reaction to this post of mine: http://www.avsforum.com/avs-vb/showt...7#post21706357

Do you have a comment about Arny confusing a jitter injection test fixture with a jitter elimination one and proclaim it exists in virtually all AVRs?


Please prove how you arrived at the 400 ps number. And walk us through what you think is happening as your description of it is vague and uses the wrong terminology.


Yeh, what about it?


Oh really. You just said there is less than 500 ps jitter in the system above. Now you say .5% to 4% jitter is induced in the digital audio clock? You sure you have your facts right?


The first sentence is true is what I said many pages back. But statistically we could get unlucky and that could have occurred in the TAS author's machine (in one test instance). Can you demonstrate how?

What what low pass filter? You have data from author's test that shows the corner frequency of their DAC? And can then correlate that with the type of jitter present *in their machines*?

Let's review what you said and my response:

------------------


Say what? There is no de-jittering block in that picture:


As we see, it is a test fixture to inject jitter, not eliminate it. They used it to determine that the Musical Fidelity's jitter filter stopped working at 5 Khz and lower. From the paragraph right above that diagram:

This technique was used to determine the PLL cutoff frequency of the Musical Fidelity DAC at approximately 5 Khz, imply that any jitter components below this frequency will be unattenuated by this particular unit and will contribute to jitter error at the DAC.

How can you not tell the difference between a fixture that *injects* jitter and confuse that with a jitter reduction circuit Arny? And then proceed to claim such a circuit exists in all AVRs? Really? AVRs inject jitter in the system?

------

The circuit "shown" was jitter injection, not jitter reduction. Will you concede that you read the paper wrong on every point you made in that post?

Yes.

No, the Dolby paper indicates the level of audible jitter under 'ideal' conditions.



True, but misleading. Uncorrelated jitter is less audible, not more audible.


Actually, the Dolby experiment is statistically biased for finding audible jitter because they excluded all individuals who couldn't be trained to hear jitter induced distortion.


Totally, and absolutely unsupportable conclusion based on the design of the TAS trial.



Pure test tones trials totally bias jitter distortion detection toward 'hearing it' because auditory masking doesn't come into play. Music is not pure test tones, and auditory masking clearly and unequivocally comes into play when listening to meaningful content.


Well, I have read it. It is a well designed study to find the audibility of jitter distortion.
The TAS study does not isolate jitter, measure jitter, or even test jitter in any fashion what so ever. Any, and all 'conclusions' about jitter can simply not be made based on the design of the study, and frankly the findings actually exclude jitter as a possible mechanism for their findings.


Partially true at best, irrelevant, and again the findings of the TAS study mostly lowers if not totally excludes this as a possibility for explaining their results.


I'm not trying to turn this into a 'prove jitter is audible' thread, but rather trying to explain why the TAS article is self contradictory, and the concept that jitter explains the finding is at best conjecture, and at worst totally inconsistent with the findings of their study.

The first rookie mistake above is Amir's fictional belief that there is just one power supply in a PC. In fact there are a large number of them, each isolated from the others by separate filtering, etc.

The second rookie mistake is Amir's fictional belief that disk drives start and stop spinning their platters often enough to affect the audio. In fact the starting and stopping of the hard drive platter is under user control and can be completely suspended for the duration of the boot.


The seek current pulse is supplied by a reservoir capacitor in the hard drive. Note that it draws current from a different supply than the PC's logic. The reservoir capacitor is an effective filter of any variations.


This impulse only exists inside the hard drive's case. It is isolated from the rest of the PC.



No such thing ever happens except apparently in Amir's imagination. There are actually a number of different timers in a PC. For openers there are separate timers for the system clock and for RAM refresh, and then there is the PC's real time clock.


This presumes that the PC is mostly sleeping and wakes up occasionally. A modern PC playing a sound file does not sleep.


Amir's fallacious assumption here is that everything that could be audible is audible. Regulars at this forum are aware of Amir's continual sloughing of this issue. Amir has never found any reliable evidence of audible jitter from this cause with his own listening tests. Big talk, no action!


Why simulate, Amir? Why not do some reliable listening tests?


Amir's idea here is that apparently you can't take numerical information about the thresholds of audibility from one kind of test (e.g. The Dolby Labs AES paper) and apply it to some another situation.

No, it would appear that according to Amir, you have to do a proper independent listening test of every different kind of jitter, no? Well if that is so, why has Amir been ranting and raving about numerical test results from AVRs? Where are Amir's listening test results for AVRs? Oh, they don't exist.

It would appear that Amir and only Amir gets to cherry pick which cases you can make judgments about based on numbers, and which cases you have to actually do the listening tests on...

Wow. Entertaining, but if you guys want to measure "manhood", take it offline.

The keyword is "reliable." You complain about TAS test not being reliable. And that is the issue. As soon as you involve humans, that question comes up. Mathematics on the other hand, is objective. You can analyze the equations and if you can't find fault with it we are done. Not so with listening tests. Folks start talking about horses doing math all of a sudden.

Simulations also cost nothing but brain power. The TAS editors ran dozens of tests. Imagine recruiting 100 people and running all of those variations through them. Any wonder then why there is not more of these tests? Folks earlier asked you and I go and run tests and both of said it is too much work. Well, it is not much work to read a paper, walk through their analysis of what it takes for jitter to be minimally audible and agree on that.

Of course the mathematical proof also needs to be correct. And it might set too conservative of a floor. As an engineer, I like that. A well designed system is not running at the edge of its performance but rather, with a safe margin.


That's right. A negative outcome can't invalidate a positive outcome involving completely different test conditions and observations.


If you want your answer to be right for all people, all equipment and content, you would need to do even more. You would need to incorporate the DACs in that equation.

Now, engineers take shortcuts all the time. As long as we are then aware of that we have cut corners, we can see if we can make our universe finite. One way to do that is to gather profile of jitter in large set of devices and use that as the stimulus. And profile DACs and maybe use a few sets of them as part of the test fixture. This is all a far cry from using a single tone sine wave for jitter and calling it done. If you do, then I say you lack rigor in your testing!


That's right. The manufacture of your gear doesn't put out any listening tests or for that matter, any measurement either. You should be asking them for that data. When I buy a speaker from Harman, I know they performed double blind tests. Not so when I buy your favorite brand of AVR.

So what to do? We fall back to measurements and threshold of audibility. The latter was generated based on listening tests. Let's assume it is valid even though it was done 80 years ago . We then compare that to our measurements and see if we fail that threshold or not. If it passes, then we know we are good to go because mathematics help prove our case, not what six people did in a room with a sine wave generator and three music tracks.

Or you could do as you advise. Close your eyes and assume the jitter is not audible. I am fine with you doing that. But it is not for me. I can just as well find products that perform to a level of mathematical certainly and not my gut feeling.


No. If at all possible, I want to rely on theory. If that fails, I want to rely on measurements. Relying on a bunch of talking horses doing math is not the way I want to base on my audio purchases on. I realize you have a different point of view .

BTW, while we are on the Dolby paper, their testing was "AB" not ABX. Do you think that indicates lack of rigor here?

And can you please tell me if their testing was single or double blind? This is how it was done:

"After the output level was adjusted, testing began and the subject was instructed to adjust the jitter level until their threshold of audibility was reached. During testing, the subject was free to use the AB comparator to compare the two bitstreams for audible differences. This allowed for further refinement of the threshold by providing the subject with ready access to a low-jitter reference. Once a threshold was reached the result was recorded. This test was repeated for all of the selected program material."

My read of it is that user fully knew which was which so it may not have even been blind. Do you concur?

You should leave first and then we will follow .

~350 posts (mostly between two people) and over 8500 views. I wonder what >8000 viewers are rolling their eyes about?

If I promise to leave this thread, do you promise to do the same?

Maybe they are learning something they didn't know before. It is hard to find a place where all of these pieces can come together and be discussed.


Look, I didn't come here to get a date. You need to find someone else to hold hands with as you leave.

Seriously... do you really think 8000 people gained all that knowledge without thanking you?

As I suggested, perhaps the "discussion" (AKA... schlong contest), should be taken offline (since it's basically between two individuals). There's a difference between constructive and destructive.

Just like the Bogeyman. Scary. Hmmm....I wonder if this irrational fear could be parlayed into profit?


Who cares? It's either audible in audio equipment or it isn't.
And that's quite demonstrable...or not.

Do you not have something better to do that baiting me with these remarks Ratman? You are doing nothing but raise the noise floor of the thread.


And your repeated posts on this front are falling in the latter category. Please follow your own advice and try to post something informative rather than inflammatory.

The report we are talking about in this thread says it is and then some. In single and double blind tests. With level matching. With 100% consistency. With grading. Across two different systems. And two different test conductors. And published now no less. And with "sound waves" coming to their ears. You always asked for blind test data related to "sound waves." Here it is.

I know. You are going to talk about a horse doing math next......

It's good to have the time delay of the forum, amirs post is usually the last one sitting there. You get the humour, then the rebuttal.

Ever meet the person who seems to be intelligent and know his stuff, but after a while you realise they are as thick as a plank in a lot of ways? One big giveaway is that they are very literal....Arny shows that last trait a lot.

Every morning I wake up to the latest example. Usually say nothing (no point, those sort of people are unable to grasp the significance of what they say as that would require subtlety and an ability to think with the language, abilities already shown to be absent as they are very literal, QED)

But hey, sometimes you just gotta ya know? And this is only this mornings....



So what did amir actually say? Take the hard disk. Every time it starts, it kicks the power supply in the knee and runs for a few millisconds to seek and fetch its data and then goes back to the quiescent state of spinning its platter.

I mean ya gotta read it right, right?? Sure, we all make mistakes of course, but try and get arny to concede a mistake after he has made it. No, he then HAS to defend it to the death, presumably because to do otherwise is to be wrong?

An alpha male is never wrong.


Good to see the old hypocrisy in full fight as usual. For sure, *we* say we would welcome new startling results, things that advance the state of human knowledge (always cast in such noble terms I hope you note) YET WHEN PUSH COMES TO SHOVE ALL WE HAVE IS OUTRIGHT REJECTION. (damn, caps lock. sorry. Tho in this case at least it kinda fits so no need to go and retype it. Still, sorry for that)

i AGREE WITH YOU ALL, IT (THE FINDINBGS) (damn damn) are probably a crock of ****. BUT, you have not shown how. I mean, by definition a new finding that is 'new' by definition will not have precedents, so any previous findings cannot be used to deny it as 'proof'.

Again, I agree. You don't really want (or should have to) go about debunking every bit of fluff thrown out. So what to do? If *you* will never set about to duplicate these findings (other than blabbing on the net) and instead rely only on faith that what you know is true then how will these advancements ever occur?

(I love the irony that, as always in life, the majority of the spectators rely on the minority of the few that 'do'. What parcentage of society 'does' I wonder. The rest just watch. And like all good obedient spectators, choose a team to barrack for and then follow that team to the death)

Well, if *we* are never going to try the replication then we need to be able to show where and why the flaw occurred. Which has not been done yet.

We can be as certain as we want that it IS there, but that is not proof. It usually comes back to as shallow a reaction as 'they must have lied'. Pretty poor proof (tho it has to be admitted it could be completely true!)

I am just glad amir can type like a mutha, else these sort of idiocies from arny (amidst all his good contributions mind) would simply get lost and exert there hidden influence.

One last thing I wonder about, why would someone who makes as many simple errors of these types as arny does continually use phrases like 'rookie error'?

I mean, would you not at least be very very sure of your grounds before you behaved as arrogantly as that?

Then again, as stated, is is highly likely he would not be able to see it anyway so this moral question becomes moot.

Great. It is a rare occasion that someone has read these reports, and even more rare that they follow it with a post that shows they have .


Where? What makes their conditions ideal? An ideal condition would include worst case jitter. Sinusoidal, data-independent, jitter is not worst case jitter.


I am glad you agree they used uncorrelated jitter and hence it is less audible . Your response however doesn't address the point that I made. In the Dolby test they are injecting only single jitter frequency. There is no evidence to back that this is the profile of jitter in real devices. Here is a random measurement from Paul Miller:



You see all of those spurs (spikes) around the main signal frequency? For a single tone in the middle, we got all of those sidebands. Not one, but all of them. Now imagine your music being made up of thousands of those main bands, with each generating all of those distortions.

Still think the Dolby test created the ideal conditions for jitter?


Not really. They may have just thrown one guy off the train. It is not like they surveyed 1000 people and out of them, they picked these 8. And the ones they picked, some are pretty tone deaf relative to the best guy. Mind you, I think it is great that they eliminate some people. Just that it doesn't rise up to the level you are mentioning. To wit, it is still entirely possible that the authors of TAS article could beat even their testers.


I was specific on where the two agree and I can quote the Dolby and TAS articles if they like:

1. They both believe, as I do by the way, that you can be trained to hear these artifacts better (AJ: take note).

2. That music selection is very important as some are more revealing than others.

I don't see how you can factually disagree with either when they are written in black and white. I am not asking you to the entire report if that is what caused you to go non-linear with that comment . Only that the TAS authors have said something that agrees with this report. Which also happens to agree with what we know about subjective audio testing in general (that content matters and expert listeners always do much better when it comes to discrimination).


There is no evidence that pure tone are best. They found it to be the case in their testing but that is because they did such a limited test. It is entirely possible that other content could be more revealing. The data is simply insufficient to draw your conclusion.

Also, keep in mind again that they used data independent jitter tests. And used continuous tone jitter.


It is true that a lot of masking is going on in music. But it is also true that you can't control what is music and masking can go away from under your feet all of a sudden, allowing the distortion to be heard. We use simultaneous masking as the cornerstone of audio compression. It works well 'till you get a sharp transient and the distortion spreads in the audio frame well past the skirts of critical bands and it becomes audible as pre-echo. Since masking effect comes and goes, distortion becomes data dependent and hence more annoying than it would be otherwise.

Well designed systems have constant quality. If your system only works when masking is there and not otherwise, then you have variable quality. And with it, lack of ability to put a number on its fidelity. We use lossless audio compression for this reason rather than lossy.

We need to also keep in mind that the Dolby test used headphones. As rightly noted in the Hawksford, when using stereo speakers masking argument becomes weaker. This is due to "unmasking" that occurs when you use more than one speaker. What worked in mono, all of a sudden doesn't work in stereo or multichannel. Both of the test systems in TAS report utilized speakers. I don't want to overemphasize this point as headphones can be wonderfully revealing too and we use them quite a bit but we should keep this in mind as another difference between the tests.

It is. It provides a data point. It is interesting though that you find it well designed even though it doesn't even appear to be a blind test. It has rather small number of testers (8?). Plus the other things I mentioned. I personally agree with you as I just said. It is a very good test. What I find unfair though is that you all look past the faults in its report because you like its conclusion, but can't in the TAS report. Terry said it long time back. We don't seem to be consistent.


How do they exclude it?


Nobody said jitter explain their findings. I have already said their finding is fallacious. So don't know why you are drawing that conclusion by arguing with me about it.

My point is simply this: you cannot say lossless files play out the same because the bits are the same. Both jitter and electrical interference cause enough variation such that this theory cannot be used to veto their results. If we agree on this, we are done. If we don't, then you have to prove that the Dolby test duplicates their condition and that you have measurement data form TAS systems that were below their findings. I think that is impossible to do.

Nope. Complete misdirection (surprise, surprise) by you. No determination (mention?) of Jitter being responsible for FLAC<>WAV findings.


Yawn. Rumored single and double blind tests. Zero cognizance of confounders or even confirmation of valid methodology. Rejection by Stereophile might be a hint. Or not.
Hmmm, where have we seen this before?? Oh yes, here: http://www.avsforum.com/avs-vb/showthread.php?t=1136745
Minus the level matching thing of course, which apparently can be circumvented when convenient...or not necessary for desired results.

Once more: http://en.wikipedia.org/wiki/Pathological_science

Ad hoc testing lends only the charade of science as cover for the nonsense.

Nope. Just another smokescreen, to hide the fact that you (still) have zero audibility test data, to supports any of your HDMI, DAC, Jitter, Power Regenerator, etc, etc, etc. audiophile beliefs. Your test data.
This FLAC<>WAV sideshow does nothing to remedy that fact.

Now Amir, one more time. Axpona, Room 513. Can't accuse me of being just an anonymous screen name behind a computer in cyberspace. yet again, you are invited outside the bubble and into reality.
First beer is on me (not literally).

cheers,

AJ