USB VS HDMI for 2ch audio to receiver - Page 2

Arny,

You cut right to the heart of the matter right there. Virtually anyone parsing this exchange and exercising some critical thinking should be able to zero in on what you just did.

It's a shame he took your suggestion about jj and turned it on its ear, trying to co-opt it to his advantage. Whether he actually did hire jj at Microsoft or not, I suspect jj would be willing to call BS on his claims about DBTs and the audibility of jitter (implicit in his discussion of it is that jitter is audible and thus relevant) in this thread.

Feel free to invite jj to this thread. I might do the same.

No denying the work aspect but if as you say the differences are most pronounced under particular musical conditions, then that cuts the time needed significantly, no?


Then you know that equipment likely requires periodic calibration throughout the day. Automation and intelligent software can allow the operator to perform other tasks which makes it less tedious. However, how do you know your body, the biological machine, hasn't changed?

Also, what do you mean by reasonably objective data? Can you expound on that?


If you look at the first quote in my post, diomania asks a pretty important question. Now you've stated you have access (doesn't mean own does it?) to speakers that not only rival but exceed them with respect to transparency. I take it that also means you've got a pretty nice room. So, looking at his question again, in your opinion which way are the odds skewed WRT the topic at hand with mainstream speakers? BTW, that Pioneer receiver kicked some serious a$$ didn't it?!

I am curious. Please tell me/us about this system.

Arny,

I'm with Will2007 on this - the direction of this thread has been amusing to say the least, and you've really hit it on the head here.

I have tremendous experience in R&D having managed development of everything from VLSI design to that of computers, analog and digital design. Ask me a question and I will answer but please don't keep putting down my knowledge and experience. I can handle it but there is no reason for it. Go after what I am posting and prove that wrong.

I said nothing regarding development costs. I spoke of the BOM cost hit which mass market products cannot stand.

You are mixing topics. Yes, the R&D budget for a mass market product may be far, far higher. Companies like Panasonic go as far as designing their VLSI for devices such as Blu-ray player. That says nothing about how much money they put toward audiophile aspects of the device. As a relevant example, Berkeley Audio burns in their DACs for a week and then spend a few hours hand tuning it including listening tests. Their R&D budget is probably tens of thousand a year. Samsung would spend 100X of that for one of their products. But I bet you there is not one Samsung product that goes through that kind of burn-in and hand tuning. Two different businesses, two different approaches.


It is true that the old PCI Lynx audio card is still revered as being great. I still have mine some place but have no use for it now that I can get better sound using async USB. And more and more people are starting to get convinced and go in that direction. Putting that aside, who said they do something bad to audio?


Sales pitch for what? I asked them to test their own gear. There is nothing to buy. It is very likely that most of them don't hear any difference which is fine in my book.


Say what? The front panel switches are momentary toggle switch. You push them, they do something. You push it again, it does the reverse. There is no mechanical feel to it as it is sampled by the microprocessor and acted upon. Are you thinking of 70s hi-fi gear?

But yes, if you can cheat by feeling the button, don't do that. You don't want to cheat yourself into believing something .


If you know you are cheating yourself, then you are cheating yourself. But if in three independent tries, you still get the same result, then you might have some useful data. Besides, I suggested you can try it on a friend who is not looking. What is your beef with that?


Boy, you seem so defensive. I suggested someone do blind test and you are unhappy with me?

Anyway , you should not be concerned. Most people won't hear a difference and will actually support your view. For select few, they will have an interesting realization.

As I was clear, their observation is not meant to prove anything at scientific level. But to get meaningful data beyond reading random chatter on a forum .


Which is miles ahead of no test which is what you are offering. And let me break the news: ALL audio tests are flawed. The good ones are simply less flawed than others. Period. Do we throw out everything they find as a result of it? I hope not. That would leave us with nothing. What we do then is to examine the test and decide how valid it is for us and what out of it can be used.


I have been a member here for far longer than I have had my business. My posts in these areas have been consistent for years. Feel free to go and ask. Chu actually knows and I am sure would chime in if I had said something inconsistent.

That said, I am glad you point this out and as people need to be aware of apparent bias in poster's views. That is why I am up front with that in my signature. You should assume that what I say may be profit motivated even though I do not make a living from Madrona. Be cautious and not believe opinions I put forth without real data.

We do. And I have a $25K Audio Precision analyzer at home. The evaluation of an audio product must be multi-faceted. Waiting for some double blind test to show up to answer your question is not a path to salvation....

What I was anxious to know was actual cases which the listeners could hear the difference of sound quality between dedicated DAC vs AVR or vs CD player in ABX. Are there any?


Are they also referred to as Golden Ears?

Sorry, I don't see anything that makes the data gathered in such way more meaningful than random chatter seen all over the net. They are both subjective observations.

Let me understand this. You run your own randomized blind set of trials at home. You use your own ears to see if you can identify if turning off some of the circuits in your equipment makes a difference. Let' say you do and in all three instances, you find out that you prefer the circuits off. You can't possibly tell me you are not smarter on that day than you were the day before about such things .

Let me say that if you had run such a test and post here, my respect for anything you would say would go up incredibly even if it disputed the position I was taking. Indeed, my top goal in these discussions is to get people to go and learn the science and experiment. It is sharing of that data which moves our collective knowledge forward. Otherwise, it is a waste of time and words.

I thought I answered that very question . So I will try a different path. What if I showed you folks hearing a difference between SACD and 24-bit/176Khz. Surely that is one of the myths that Arny likes to debunk. Would that be of value to you?

Mistakenly, sometimes. A trained listener is someone who has gone through a formal process of qualification and training for a specific set of tests. You can read Sean Olive's excellent article on the topic: http://seanolive.blogspot.com/2010/0...eners-and.html

Golden ear is someone who has a better than average ability to hear differences between audio gear and I guess, recordings. There is no formality to it as there is for trained listeners.

It would be my pleasure to describe it . Here is a picture of it:



Working backward, Speakers are Revel Salon 2s. Amplification is via two Mark Levinson No 53s or the reference 532 (latter sitting on the cabinet). We skip pre-amp and feed it directly from the Berkeley Alpha DAC (in the cabinet). Feeding that is the Audiophilleo asynchronous USB to S/PDIF converter (tiny box the size of a deck of cards hidden behind the cabinet). Finally, we get to the touchscreen Lenovo PC that is on the wall which we bought at Fry's for $800.

I trust Arny is proud of our choices there, seeing how the Revel speakers were designed and optimized heavily based on double blind testing. And the 53 amplifier went as far as having an emulation of it built first and blind tested before the actual product was built and again blind tested.

The Berkeley Dac was built by the founders of HDCD technology -- Pacific Microsonics -- which I had the pleasure of acquiring into Microsoft/my team. Hopefully you have heard of the great work they have done with the likes of "Prof" Keith Johnson who won an Emmy award this year for his recording wizardry. No blind testing in this camp though. I like this DAC because by audiophile standards is reasonably priced and has a nice built-in volume control saving us as much money as it costs in pre-amp.

So there you have it. A very minimalistic system designed to do the job and no more. Yes, few of us can afford it . But nice to have such tools "at work" nevertheless.

From what I see, you've answered it indirectly with alternative samples. I was asking for straight cases of comparing dedicated DAC vs AVR or dedicated DAC vs CD player for sound quality difference. Reason being, just because AVR or CD player has video circuits and or front panel display, does it always mean dedicated DAC has a leg up on them? We shouldn't rule out the possibility that AVR with all those extra circuits may be just as good as a dedicated DAC but even better when they are turned off. Given such possibility, I have a hard time considering your suggested experiment as a viable alternative to straight comparison of the two components.

So, are there cases of straight comparisons for audible sound quality difference of those equipments?

I didn't think I did. This is what I said first time:

"They are not going to find their favorite AVR compared to their favorite DAC."

I said DACs "tend to" have an edge. So no, they don't "always" have an edge. Indeed, a cottage industry has been created where people take any old DAC, stick it in a box with a power supply and call it done. Most of them lack any test equipment to measure their performance. So there are as many bad DACs probably as AVRs. Nothing replaces an educated customer in that regard.
True. If I told you the odds of getting certain card in Black Jack is 30%, it doesn't mean it can't happen. It simply means it is less likely to happen. If you were to close your eyes and pick an AVR or dedicated DAC, my suggestion would be to put your money on the latter . Knowing that you could be wrong due to blind selection.
That comparison was not put forth to make that argument. But rather, designed to find out if there could be a difference in extra circuits or not. We have to believe in that basic fact, before believing that a DAC that is devoid of those circuits could be better. In other words, necessary but not sufficient condition.

I don't know of any.

I'm a curious sort of fellow. Quite skeptical even in matters unrelated to audio. Not too long ago, Berkeley Audio came up in a different forum on this website. I searched their corporate address and Google maps indicated that it was a home in California. I don't know quite how they develop their products as I'd think you'd need some sort of an outside facility with appropriate testing capabilities. Maybe they contract the work out to someone? I just don't know how much of what you've said is BS Amir. And I don't mean you. I mean Berkeley which I take it is where this burning in and hours of hand tuning comes in. Could it be what's really meant is that the actual DAC (their product is far more than a DAC I think) goes through a testing process designed to weed out failures? And the few hours of hand tuning was actually done in the final stage of product development which included listening? After that, they crank em out as needed in order to fulfill minimum production runs? What I'm asking you Amir, is how do you know exactly what they mean by those terms?

Amir speaks the truth. Long before he entered into an audio business related venture, his comments on matters such as those in this thread have been consistent. Myself, I don't see his participation in these sorts of discussions as sales shacking. If part of what high-end is supposed to mean is the most faithful, do as little damage as possible to the signal regardless of whether it's audible or not, I can appreciate his position. I can also appreciate that with judicious shopping, those of us who are financially constrained in this hobby can put put together a system that was unimaginable 30-40 years ago. I hope Amir continues to post and continues to find the time to respond to questions as well as offer his perspective.

I've been in touch with JJ and he is aware of what is happening here. He confirms what has been said here about their relationship with MS.

You may have hired JJ but you didn't get to know him very well.

AFAIK JJ gets *no* pleasure from beating up innocent audiophiles. His involvement with deunking is similar to mine - we *are* audiophiles, we *like* audtiophiles and we don't like to see them mislead or cheated.

It is easy enough to find people who intentionally or unintentionally mislead and/or cheat audiophiles. The effects of common audiophile trash talk and bogus equipment promotion on the audio industry has almost paralyzed it because there is now so much crap.

You've already proven that despite your initial claims you have about zero clue about what constitutes a proper listening test, and you are quick to advise people against them.


I never said that you did.


Another example of how you only tell the truth that favors your viewpoint, despite a larger picture that tells a different story.


I'm looking at the big picture.


Given what "audiophile aspects" means today, I would heartily agree with that, especially since I personally own a Panasonic Blu Ray player. The absence of a cut off switch for the front panel display causes me not one little bit of frustration.



Sigh. Equipment burn in! Yet another audiophile myth. Saying that a piece of gear requires a burn in and readjustment is a tacit admission of either poor design and/or parts quality, or simply trying to sell a product based on mythology.


Given what the need for a lengthy burn-in and resinspection says about the poor quality of their parts and design capabilities...


No, one is a business and the other is a hobby-horse factory based on anti-engineering or audiophile myth.


Here's a news flash: the old PCI Lynx One was replaced by the LynxTWO some years back.


I need not fight with you over USB audio interfaces when I have caught you criticizing every Blu Ray player that Panasonic makes on the grounds that they don't get lengthy burn-ins.


Sales pitch for your hobby horse - you made a sales pitch for the audiophile myth that front panel displays always hinder sound quality.


It was a trick. You basically said that if they had a really good DAC that it would have a switch for turning off the front panel display. Since only a tiny faction of all DAC products have such a switch, you were casting seeds of doubt in the minds of maybe 99% of all readers of this thread.


You basically inferred that if they couldn't hear the difference they were somehow deficient.


You don't push toggle switches. You push push-button switches. You're not telling a consistent story.


Your adverse comments about doing good listening tests say otherwise.


You are trying to turn an equipment fault (display trashes the audio) into a desirable feature.


I see the bigger picture where you advise against doing proper listening tests, and have been making false claims all along about your own alleged blind tests.


There you go again - you try to make heroes over people who actually spend money on placebo effects.


I suspect that you are highly confused about science. When you make claims about the audible performance of audio gear you are in the world of science, no matter what you may try to suggest. You are saying that this is how the real world works, when in fact the truth is something else.


...it appears that we would have to teach you a lot of science. You already admitted that you have no clue about the science of psychoacoustics. We must add experimental design to your curriculum. Etc, etc.


I just wrote that in another well-known forum a few days back, so we now can disregard your claims that you have studied who I am with any degree of thoroughness or adequacy.


That is of course true of any scientific endeavor. All findings of science are provisional, in that they are most relevant only until more relevant findings are obtained.

But when it comes to the flaws that are inherent in the sighted evaluations that you are trying to sell here over the dead body of blind tests, we're not comparing things whose flaws are comparable. Sighted evaluations for subtle differences are horribly and wretchedly flawed, while blind tests are good enough to have been responsible for a lot of the advancements in audio over the past 20 or so years.


No, we just throw out the well-known audiophile myths that seem to be much of your stock and trade.


No what's left is what actually works.


When it comes to sighted evaluations of the kind you've been proposing recently there is very little reliable information that they can reveal. The long list of audiophile myths that you have been using to support your self-serving bias against HDMI is proof enough of that.

The real problem with mainstream audio products is that a small high end shop can't compete if they try to sell them. I think it would be fun to pick the *worst* AVR that Mr. Miller tested and do a blind test involving you as the listener. A *real* blind test, not some highly flawed sham. ;-)

If JJ is aware of this thread, I wouldn't mind it if those who know him were to invite him to participate if he has the time.

I was not suggesting what "constitutes a proper listening test." I was suggesting a test anyone can do at home with zero expense and very little effort. You continue to twist my words to defend your position. That type of debating tactic may have worked in high-school but won't work with me. I will keep correcting you as many times as you make it, which seems to be a ton.

Looks like your strategy is to take an example like the above, transform it into an entirely different context and then claim, "look, he doesn't know what he is talking about. I win!"

I have asked three times and I will ask again: in what way a user is harmed with blind testing of his own equipment. And while hopefully you are thinking of the answer, remember that there are two outcomes: 1) he finds no difference or 2) he finds a difference. Please walk us through why either outcome is of no value. That is what we do in science. We examine such things.


Now I am worried you are not even reading what I write. You are in such a hurry to repeat your cliché arguments that you skip over the specific points I make which differs than the usual banter.

The context here was whether the need for HDMI makes the problem of getting audio right harder. So the top clearly was an AVR whose video circuits you can turn off. In addition I asked that front panel circuits to also be turned off. So if you thought I was talking about doing that to a DAC, you misunderstood the experiment and ran off with that for no reason.

It would be silly for me to assume that the non-believers here already own a stand-alone DAC. Don't you think?


I don't rely on inference. I am blunt and direct. You have doubt about what I said, please ask me to clarify. Don't assume it, especially incorrectly, and then run off and call me a charlatan.

Are you telling a consistent story? You said I could feel the current state of the switch by mere touch. Now that story is gone and replaced with me not knowing what I am talking about. Here is what I know:

A switch on just about any modern AVR is a momentary switch that has no state by itself. It either makes a contact or not. A Microprocessor monitors whether that switch has been pressed or not. It then keeps "state," remembering what mode the unit was powered on in and then reverses that setting every time you push the button. If you are claiming it works otherwise, please take the time to explain. You repeatedly say I don't understand engineering as well as you. This is your opportunity to prove that point.

I am going to assume you know better than to dispute the above. So for now, for your assertion that I can feel the state of the button to be true, I need to be able to sense what number is stored in the microprocessor memory location (1 or zero depending on the state) and/or what is lit in its display. Is this what you are claiming?

This is a simple question and goes to your direct point regarding distortion in the test. There are only two answers: my explanation of how a button on an AVR works is not correct or b) there is a way to feel the state of the machine by mere act of touching it. If neither is true, the experiment remains pure in this manner and your understanding of modern consumer electronic design is below basic.


I am still waiting to know what is not "good" about the test I suggested users run. So far, then only thing you have said is that they can feel the state of the button with their eyes closed and that if it is not ABX, it is useless. Those are not positions I have ever seen anyone in your shoes take on these points. I am dying to learn more. Will you please explain?


Ah, so "modern" equipment that people buy day in and day out, has a fault? Isn't that opposite of your first post in this thread? If the test that I suggested lets people find faults with their equipment and give them a powerful new tool in shopping for equipment, how is that not "good?"


So "sell" was used figuratively in your speech. Good to have that clarified. Further, your definition of "sighted" extends to me having someone's eyes closed and hitting a toggle button on a computer controlled device for AB comparison.

Can you please tell me how then it is not invalid just the same if I am hitting the button an ABX control box? Or buttons on the UI in a ABX program? After all, if I can "feel" which state the microprocessor is in an AVR, I should be able to feel my way there just the same. You are not saying one computer is more capable of hiding its state than another from human touch, are you?

I will stop here and keep this post focused 100% on the experiment. Let's see if we can specific and concrete answers from you on this topic.

I really appreciate staying on this one topic in responding to this post as I have. Thanks in advance.

I've got no problem with folks doing experiments at home, Amir, and arriving at their own conclusions. But to do the tests properly and with due consideration for those factors that can lead to erroneous results is not trivial.

Well, both of us are happily married so dating him was not going to be kosher.


Oh he does. 'cause I do too regardless of whether I go after their camp or yours . That is the whole reason we do these fights. It is fun. As males, we have the urge to go and fight for food. And "food" here is winning an argument. We have traded our arrows chasing animals for words on a computer keyboard in a forum. Why else spend all these ours just typing all this stuff? It is not like the world at large cares.

What's silly is that we don't acknowledge it. I am sure if your are married and spouse asked what you were doing your answer would be "I am working." 'cause you sure as hell don't want to say you are trying to win an argument with someone you don't even know!




Good to know. I am still trying to see how they are cheated though by teaching them to run blind experiments on their own equipment and properly explaining how technology works.

On that front, you made a number of technical claims on the first page. I corrected those but have not heard from you as to whether you agreed. For example, you implied that the DAC clock is fully independent of the input interface and hence immune to anything that occurs on that. I explained that from architectural point of view, what you thought cannot work. Do we now agree that your understanding of HDMI was flawed in that manner?

You say it is important for audiophiles to not be mislead with incorrect information. I believe in that even more than you do. Hence the reason I like to have clarity on that topic as it gets told over and over again. This is your opportunity to prove that you believe in what you just said. And that you don't throw an assumption as a replacement for facts.


True. Sadly, we are all human and do make mistaken assumption about equipment we have not designed or truly understand. I have done that myself and had to accept being corrected. No shame in that really as next time, I will be smarter for it.

Right. So answering your previous question, it does take energy and effort to conduct good blind tests. Hence the reason I, and frankly anyone in the business, relies on multiple means to move forward.

For example, as we were developing audio products at Microsoft, we would conduct large scale double blind ABX tests maybe once a quarter. Then maybe once a month we would do that type of test within the audio group alone. In between though, we did a ton of sighted tests. We would make a change and use trained listeners to quickly assess if the test was for the better or worse. Was there risk of bias? Yes. I have documented my own embarrassing moments in that. But most of the time, we didn't and progress is made.

That is how the real world works. We simply cannot afford to base every design decision on statistically valid ABX type of testing. If we did, we could not ever produce a product. So as painful as it might be for some, we have to accept that even the most ardent advocates of ABX testing, will put aside ideals when it comes to product development and cut corners to get something done.

By the same token, if the person has never done any testing, can't possibly believe that a digital system performance can be changed by mere fact of turning of a video circuit, we have forward progress in the test I suggested. If for nothing else, to learn how tedious and boring it can be with just one person involved and not keep demanding others go and run a bunch of them to satisfy them!

It may be that I'm misunderstanding the test you're proposing (switching the video processing on and off repeatedly and determining preference), but it appears to me that for the experiment you're proposing, the probability of a given outcome (call it A or B) by guessing is 0.5. That is, one does not know whether A is "processing on" or "processing off", but one does know whether it is A or B that is selected at any given time (or else the user would not be able to keep track of their choice). Also, once the correspondence between A and "processing on/off" is established, that relationship is constant throughout the experiment.

This is not a proper test. To correct this problem, the choice presented to the test subject must be randomized, so they are comparing X with Y at each trial. But they don't know whether X is "processing on" or "processing off", and this relationship must be randomized for each trial. Then the number of trials can be chosen so the probability of picking "processing on" or "processing off" by guessing is negligibly small, not 0.5.

As to whether the user is harmed (as in, "no audiophiles were harmed in this experiment"), they of course are not. The problem this causes though, is the creation of a false impression that a given conclusion was reached by a properly designed experiment. I've seen people's posts where they claim to be able to distinguish two subtly different configurations in a blind test, but upon further examination one finds the probability of reaching this conclusion by guessing is 0.5, not negligibly small. So the potential harm of this approach is the spreading of misinformation under a guise of "scientific inquiry" - a common technique used by high-end audio vendors.

You know, I wouldn't be surprised if they are still working out of their home! I have have started a company that we have been running for three years and half the time I am working at home in my pajamas . Yet we have serious interest in our solution from major companies.


Well, they have plenty of access to such things if they don't have it in their place of work. To wit, Keith Johnson has extensive access to recording studios, Spectral, etc. that could be used. But I am just guessing. I don't know if they have a testing facility for listening tests or not.

For measurements though, you don't need anything. Just a desk and some measurement tools. Mine fits on a standard office desk despite its sophistication.


Manufacturing? For sure. That is just about everyone does these days. In-house PCB assembly and such is not just economical.


You should assume all unless I can show otherwise .


I do know that answer because I have spoken to them and know the history. Let me explain.

When we bought Pacific Microsonics, it was not for their hardware business. They were building this world class ADC/DAC that was being used by major recording artists and engineers and folks were raving about ("Model Two"). Our interest was in an algorithm Keith Johnson had created to correct for flaws of cheap computer speakers. We thought we could use the power of the PC to make those speakers sound better at no cost to consumers.

But we couldn't just buy that. We had to buy the whole company. So I toured the factory and was unpleasantly surprised how much time they were spending post assembly, fine tuning the box. They had an elaborate listening facility and people like Kieth and their techs would spend days optimizing the design before they shipped it. I was terrified that we could not find another buyer for the hardware business as they would not have such expertise.

So when it came to us carrying the Berkeley Alpha DAC designed by the same people, that was one of the questions I asked. Answer was that there was similarity to the above process but much more streamlined. And that they still did the listening and optimization test. I was told it is a few hours. So while for sure reliability issues are also found in the process, that is not the sole intent.

If you look at the design of the box, you see that it is distinctly non-audiophile. There are no massive toroidal transformers in there. No big and heavy box. Just a simple power supply and a couple of boards. So in that sense, it falls in a category by itself.

My trust in this box goes to the people I know who worked on it. I lived with them for a year post acquisition. I don't think anyone has taught me new, fundamental thoughts about digital audio more than Keith Johnson. And he is not a digital guy!!! He did get me to step back and think at the non-trivial level of what can be impacted and why. Once your stereotype views are shattered, your mind is open to learn more.

All of this said, I cannot defend their design practices as it is not nearly as science based as say, what comes out of Harman. I used them as an example of what audiophiles product companies do that costs money -- nothing more.


Thank you Chu .

I am proposing textbook blind AB testing. Nothing more, nothing less. Listener is unaware whether they are listening to the system as is, or with the modification (video turned off).


Depends on your definition of "proper." What is the #1 reason we use blind testing? To remove experimenter bias. "I know video circuits do extra stuff so they must by definition worsen the sound." So I convince myself that when I hit the button, all of a sudden the sound gets better, the highs clearer, the mids engaging, the soundstage widens, and bass gets tighter .

Blind AB tests reduce the impact of such bias substantially. You don't know which state you are listening to so it is hard to try to cheat. Don't believe me? Set up an AB test and tell me how you managed to cook up the results so that it comes out the way you intended.

The choices are randomized in blind AB tests just the same. There is no hidden reference so we lose value in that, but randomization is there.

I suggested multiple tries just the same.


The same happens in ABX test if you run one trial: http://en.wikipedia.org/wiki/ABX_test

"If one ABX trial is performed, a confidence level of only 50% is achieved, the same as flipping a coin. "


There is no misinformation spread. The testing is done by a person for their own use. I have said this repeatedly and it keeps getting ignored. I was abundantly clear that you cannot take your results and expect to get published in AES or change the direction of these debates.

Once more, this was not put forth as the preferred scientific method a product should be evaluated. It was put forth as a method for members here, to decide for themselves if it is at all probable that turning off these circuits can make a difference. No more.

No one is trying to justify AB tests as being ahead of ABX in validity. Where they are valuable is that they are easier to perform. Can you suggest an ABX version of my scenario that anyone can run at home? No. It would require modification to the equipment and a computer controlled test gear.

So please don't run off with Arny's school of debate by elevating the point beyond what it was meant for and then say, "see, you are wrong." Read my original post and see how clearly I positioned it.

Okay, but let's say there is a pushbutton, such that "in" is "processing off" and "out" is "processing on". The user doesn't know which is which, but if that relationship doesn't change during the test, then the probability of choosing, say, "processing off", by guessing is 0.5. If it's simply a toggle that has no physically recognizable state, I don't see how the test subject can record their preference in any trial in such a way as to be able to trace back which state ("processing off" vs. "processing on") was chosen as a preference. If there is, please provide an explanation of the protocol.


That's certainly a necessary condition for a proper test, but not a sufficient one. Any test for which the probability of reaching a conclusion ("processing off" is better than "processing on" for example) by guessing is 0.5 is fatally flawed. The test needs to be structured such that said probability is negligibly small.


If you have an "in/out" pushbutton, the probability of reaching a given conclusion is still 0.5 regardless of how many trials are performed. If the pushbutton has no recognizable physical state, there is no traceability of which alternative was actually chosen in any given trial.


Well, in this particular case, the misinformation is confined to the test subject until such time as they post their results in a forum.


I'd argue an experiment for which a preference of, say, B to A is established using a technique for which the probability of reaching that conclusion by guessing is 0.5 is a fatally flawed experiment, good for nothing at all.


I am not claiming ABX to be necessary. Indeed, I've said nothing about ABX at all. If it's preference that one wishes to establish, then it seems to me that AB is fine. But the experiment needs to be properly designed (per what I've said above regarding the probability of reaching a given conclusion by guessing). I don't see any way of doing even a proper AB test without modifying the equipment.


Edit: Sorry, I should have been clearer about the probability thing. What I should have said was that the probability of correctly identifying, say, "processing on" 100 percent of the time by guessing should be negligibly small. In the pushbutton example, it's 50 percent, because someone could just say, "I like 'pushbutton in'", and choose that alternative for all trials.

OK, now for the rest of your points. What did I say about hunting for food?

Really? At our showroom we carry products from two companies Harman and Paradigm/Anthem. Harman has practically written the book on the need for proper ABX testing of products. They have the only lab of its kind for example, for ABX testing of speakers with robotic switching systems for speakers behind black curtains. That pioneering work came from the post graduate work Floyd Tool at Canadian NRC large scale listening tests were performed to truly understand user preference for audio. Same work was the foundation of what Paradigm uses for their science and design.

Here is a picture of the Harman facility, showing the speakers behind the curtain and the mechanism to shuffle them in under 4 seconds:



Both companies produce high-end products. Can you please explain in what way their are "hobby-horse factory" and anti-engineering?

Yes, there are a ton of audiophile companies that don't have the means to test what they produce, and as a result, have poor or inconsistent products. But you cannot generalize that to the entire industry and hope to win an argument. It is like saying there are number of car companies who product unreliable products so all cars are unreliable as a result.

I didn't criticize it. You keep taking a statement, adding two to it and saying that is wrong. I said they could not afford to do audiophile things since they have to compete on price. So by definition and design criteria, they do not go where audiophile companies without price, weight and size restrictions can go.

"Always?" Show me the post. I said the opposite. I said they could just as well find no difference. Besides, who is to say every person here is an audiophile?


I don't know who reads this forum. If they are buying placebo effects, then they are not going to run my blind tests. On the contrary, my suggested test was for non-believers. Believers don't need additional proof .


I can't spell worth a damn sometimes. Can forget words here and there. But I am pretty sure I did not admit to any such thing. If I did, just quote it for me.


Yet another debating technique: I will imply you will flunk the test so that proves my point. Let me spoil the surprise. I could easily flunk such a test. And I have actually as I am human. I make mistakes.

Folks have proven that my subjective evaluations have been wrong in blind testing. I have documented that publicly. And I have proven them wrong in blind testing where I found differences where they thought no one would including all the others who they had tested blind. I have also documented that. I am an open book. I am not afraid to be wrong. So please don't use that fear tactic with me.

Anyone who thinks their ears is as precise and repeatable as an instrument, is delusional beyond any audiophile might be. Or they have not been in as many blind tests in tough areas where differences are small as I have.

Instead of war words and hypothetical future tests, how about you commenting on this test: http://bryston.com/pdfs/07/Swedish14BSSTReview.pdf

It should pass as a proxy for what you are challenging me to do.

And, comment on Michale Fremmer being able to tell 5/5 times in an AES workshop on blind testing of amps: http://www.hydrogenaudio.org/forums/...dpost&p=629443

I am no fan of the man and certainly not the unprofessional way he posts but his comments do make you go "hmm" .

"Let me answer Mr. Krueger's fantasies:

There was an AES meeting back in the early '90s and an ABX test of amplifiers. I was involved because I claimed that the idea that all amplifiers sound alike, or pretty much alike (that measure the same) is kind of foolish, since we really don't measure every aspect of performance and I told David Clark to produce an ABX test and I'd be happy to take it.

I took the ABX test as devised and produced by the group and I got five of five identifications correct. My editor, John Atkinson got 4 of 5 correct. The average of all test takers was inconclusive. According to Dr. Stanley Lipschitz, I was a "lucky coin" and my result was tossed.

So much for "science."

Now, here's the funny part: among the amps were some steely sounding solid state products including a Crown DC 300 and a very warm sounding VTL tube amp. It was quite easy to hear the difference between those. For one thing, they surely won't measure the same!

However, the average test taker, which included many recording engineers, could not, under blind ABX conditions tell the difference! Having been involved in many such tests, I brought more experience to it and so performed better as did John Atkinson.

I am happy to take such tests and usually do very well taking them...I can show you results of speaker identification blind tests I did at Harman's research center."

I don't want us to re-live that thread without all of the same participants. But did want to note the above posts which was linked to another thread at another forum where we were discussing similar issues.

As if me posting something has resulting in folks accepting it despite years in this business .


I disagree and too tired of typing to explain why . Just leave you with one fresh thought.

You do the blind test and time after time, no matter how many times you repeat it, the one that you like is with the circuit off. Question: which way would you leave your equipment? With the circuit off or on?

Second scenario: your car manual says that you put premium gas in it. You one day decide to put regular in it. You drive and it and it feels exactly the same. You do that 10 times in a row. Assuming I guarantee you that there is no damage to your car (and buy it from you if there were), will you pay extra for premium fuel or go regular? Crossing fingers that the proverbial car analogy doesn't come back to hunt me.

My entry to this thread was on your reply on the first page where you said, "It means that to get equal audio performance in an AVR, you may have to spend a lot more money than a dedicated audio DAC. And even then, you may not quite get there.", which made me wonder how that came about. But, now that there hasn't been straight comparison results to support your notion, it's safe to pass that off as just a speculation about dedicated DAC based on jitter theory. On the other hand, based on the limits of human hearing ability, people can also speculate the opposite of your notion about dedicated DAC.

Now, if someone can cite some examples of ABX between dedicated DAC vs AVR or CD/DVD player, that would supports one of the two speculations we are dealing with thus making it a stronger case. I remember going through pages of such comparisons in a site called Matrix-Hifi but it's in Spanish though.

Misinformation is misinformation, regardless of whether or not people accept it as true.


Well, this is a different question. The earlier discussion centered around whether the test was "proper" (my words, maybe "valid" is a better choice), and this question relates to whether one would use the results of an invalid experiment anyway, knowing full well it was invalid. I plan on using an HT pre/pro for an audio-only system (just for bass management and possibly room correction), and I will surely turn video processing off if I have that option, just in case it might make a difference. But that is my own personal choice, and I would not try to make claims about its effect in a forum.

Arny is bad at debating tactics but you are an expert . But fortunately, it is not so simple to draw the conclusion you want. You asked me about AVR vs DAC test. That has nothing to do with limits of human hearing ability. Such a test simply does not exist. Lack of its existence is not proof of anything. It simply means we have no data. So don't use it as a basis for anything else.

Besides, you did not ask me to prove the limits of human ability. You asked me about a specific test. I actually offered the opportunity to read about this topic in comparison of SACD and DVD-A. You refused. Why? It is not logical to be interested in the topic, yet to refuse to learn more about neighboring topics.

Since you decided to hugely expand the scope of your assertion, I feel free to ahead and post that published study without your permission :
http://old.hfm-detmold.de/eti/projek...paper_6086.pdf

"DVD-Audio versus SACD
Perceptual Discrimination of Digital Audio Coding Formats
Listening Comparison Test between DSD and High Resolution PCM (24-bit / 176.4 kHz)

by
Dominik Blech and Min-Chi Yang
Erich-Thienhaus-Institute (Tonmeisterinstitut), University of Music Detmold, Germany"

The test was ABX and designed to see if anyone could tell the two sources apart. Almost no one did except for four people:


"The four highest scores fell into the region of critical
probability. This amounted to only 2.76% of all the
tests. These four tests were carried out by four separate
listeners, all of whom chose stereo music examples, and
in all four cases headphones were usedthus excluding
the influence of the listening environment to the greatest
possible extent."

And this brings us to an important point that people like Arny forget: we are not attempting to prove that all people hear these differences. That cannot be proven. General public has pretty low threshold for fidelity. Get there and they are good to go.

What we are trying to establish that there can be differences that a few people can hear. In that sense, it does not matter if 10,000 people don't. They are not here searching for the next best audio equipment to buy. Granted, we don't know if any one person falls in the bucket of the four above. But that is for them to decide and learn.

Net, net, it is critical to look at the data and not just summary results. Averages and means have been used for years to paper over the details. Sometimes that is OK. It is not here.