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12.162.213.5
A good idea or not?
My thoughts:
1- No fan
2- Not much CPU power needed.
3- Easily portable between different systems.
I have all my music on a music server encoded in Apple Lossless (and kick myself because I shoulve stuck with FLAC)
navman
Follow Ups:
Gets Blamed for everything that does not have a concrete rational reason. Its the Boogie man, Jitter is something man has seen gave a name to and attributed all kinds of nasties to it. Basically its just want you get when you can not get this packet of date to than place in an instant...that lag time is jitter.
I think we need to sent this off too Steven Hawking to figure out once and forall, he should be interested in the quantum state audio has gotten itself into these days.
In the mean time, everyone has an 'ANSWER" and an "EXPLANATION".
Kind fun watching all these geniuses clambering for the right answer while at the same time slamming others.
Music is the Bridge between Heaven and Earth - 音楽は天国と地球のかけ橋
Gang,
First I love my ASUS Netbook. I have both the 1000HA and the really upidy ssd version S101H.
Both of these are ok, really ASUS did a great job with these I have more good things to say about these than I do Dell or any other full laptop.
But using these with lossless files is a bad thing....
two points
1) They are under powered to optimize them.
2) Switch from Lossless to flat PCM (WAV/AIFF).
If you used iTunes get one of the newer ASUS with Windows 7 and use WASAPI mode with iTunes to get much better results. You can set this in the options for QuickTime.
Thanks
Gordon
J. Gordon Rankin
Hi Gordon,
I also like my Asus netbooks! They do have fans, but since I am deaf I can't hear it. :) I run Win 7 KS or WASAPI and I am satisfied.
Bob
VooDoo Alert.
P
I have heard a difference between FLAC and WAV/AIFF files on my lower powered computers. The difference may not be significant to the listener.Gordon and everyone else knows that these computers can play FLAC files with no problem. The sound quality is what he is referring to. Again, there may be no perceived difference given individual listener's preferences.
Edits: 02/27/10
"Gordon and everyone else knows that these computers can play FLAC files with no problem."
-- I'm not so sure that's true. Boards like this one tend to have a lot of lurkers who don't post much, but come to these places seeking knowledge of computer audio and wisdom regarding what does and does not make a difference and may or may not be a good investment. Guys like Gordon, being manufacturers and speaking, as they do, from a place of assumed authority, may get taken very seriously by these folks. Why wouldn't they when these people speak with such certainty about what is so uncertain?
"The sound quality is what he is referring to."
-- Yeah. I get that, and if a lossless file doesn't sound the same as FLAC, I wouldn't call that playing it "with no problem." YMMV.
"Again, there may be no perceived difference given individual listener's preferences."
-- I get that, too. Though I'm not so sure everyone in this conversation does. Do you really mean what you said? That "listener's preferences" determine "perceived differences?" Break that down and that says "what you prefer, you will hear." That actually might be close to the truth, though I doubt you meant it that way.
In any case, Gordon and others here talk about this stuff as if it isn't even questionable, as if these differences they "hear" are what is widely accepted, tested and confirmed by the bulk of the evidence, when the opposite is true. It's like that bizzaro world in the old Superman comics where up is down and black is white, and those of us who actually have the evidence on our side bear the burden of proof.
And now it's time for me to be accused of having an agenda, or bad kit, or bad hearing...or for Carcass to simply come along and throw some abusive language at me...never mind...
P
Let's see here...
1. Agenda? Check! I hope you won't be denying that - and if you have an urge to do so, I recommend re-reading your own posts first.
2. Bad kit? Check - at least one, for AVI ADM9 (don't know, and honestly don't care, what other "value leaders" and "giant killers" are there);
3. Bad hearing? Possible - or rather #1, combined with #2, takes care of things so well, that hearing doesn't really matter.
I would also add #4 - excessive frugality, that is lurking somewhere there, adding to overall grim outlook.
How'd I do?
P,
Ok here's one that will hurt. I take it you are a Windows person. Take Foobar WASAPI/EXCLUSIVE mode and play a song. If setup correctly it will be bit perfect. Then do the same thing with J River same files...
Tell me why do they sound different?
Enable RAM buffering on J River, changes the sound even more.
Heck now we are only changing the application, not even the file content.
Both are bit true...
Tell me why?
Same thing for Amarra and iTunes on a MAC. Both bit true... both sound different.
Heck in that case you would think Amarra would be harder on the system as there is both the overhead of the processes of Amarra and also iTunes...
Go figure...
Thanks
Gordon
J. Gordon Rankin
I'm a Mac guy, Gordon, and I have downloaded the Amarra test. Switching back and forth between Amarra and ITunes, I can't say I could pick accurately more often than I would have chosen by flipping a coin. So many have commented so strongly on Amarra that I don't quite trust that result, though, and expect I had some compatibility problems.
You hear what you hear and I won't question that. The problem I have is when you imply that these differences, unsupported, unexplained, unmeasured and untested, are well-established. That is simply not the case.
P
P,
I probably have brain rote for how much freaken test equipment I have within 10 feet of me.
I have described how and what we tested and the conclusions from numerous shows from average people with staggering numbers.
If you don't agree prove me wrong.
Thanks
Gordon
J. Gordon Rankin
You have measured and published differences in the analog audio coming from two different, properly-functioning computer systems through the same DACs and playback systems? Point me to the publications! I have to assume they're in some very distinguished journals, as this would be a scientific breakthrough.
P
plus the controlled ABX tests showing these differences to be statistically identifiable and valid.
If those unsupported, unexplained, unmeasured and untested differences somehow were magically supported, explained, measured and tested - what would that change for you personally?
Would it make you think about the quality of your system and/or hearing? Would it force you to spend some money, to give yourself a chance to hear those differences for yourself?
Or, at the very least, would it make you refrain from posting what you usually post here?
Kind of doubtful - on all counts...
c) All of the above.
P
Why do you need some kind of confirmation, approval, affirmation etc. from some people who are NOT YOU, doing tests on audio systems that are NOT YOURS? How results of those tests, positive or negative, could possible mean anything to YOU personally? This just sounds bizarre, frankly.
Measurements are different story (more objective), but would it be wise to put too much faith into a set of measurements, whose completeness and relevance are questionable at best?
Too put it differently - what prevents you from starting doing "all of the above" right now?
we have a measure of agreement!
What people hear in their own homes is their own business. Whether folks want to waste $1K on powercords, or buy any of Machina Dynamica's garbage, or tack black wooden discs on their walls, is totally up to them. I wish them all the best on their audio endeavors, and much listening happiness.
But, one objection lies with folks, amateurs and professionals alike, regurgitating unproven/scientifically doubtful/highly questionable statements of causality as fact, or that XYZ factually makes a difference, when they aren't factual. This type of nonsense hurts the industry as a whole, to the detriment of the induction of new audiophiles. Non-audiophiles hear these things, see the gigantic prices on the equipment, and run the other way thinking audiophiles are mad. This is where audiophiles could do with some readings of the many available online issues of The Audio Critic and AES papers.
Another objection lies with tweak makers and other purveyors of audio BS selling their wares in ways that amount to nothing less than consumer fraud. The only reason these ding-dongs haven't been shut down is because their corner of the business world is insignificantly tiny. If Bose made the claims the mad-hatter tweakos do, they'd get hammered by the DOJ and State attorneys general.
If you don't mind, I won't be commenting on your last 2 paragraphs - except may be for the question why would you give a damn about induction of new audiophiles. To switch perspective a little - when I sit down with a glass of 16 y.o. Aberlour, am I supposed to think about induction of new single malt drinkers?For the record - I personally don't own Machina Dinamica products. The most expensive power cord I own was only something like $440 (used), however I'll take solace in the fact that it'll probably still qualify as waste on your scale of values.
P.S.: I thought you would enjoy, and may be want to comment on, the post linked below. What makes it special - the guy apparently is (was?) one of "yours".
Edits: 03/02/10
Too many variables. E.g., it is unknown whether the stock cords were able to deliver the needed current (which they probably were), and total lack of comparison testing. The single fact that he descibes an earth-shattering, enormous difference in sound from replacing one generic cable with another suffices to discredit the poor fellow.
Plus, it sounds like the dude fetishized having poor Erykah Badu standing in his bed. Perhaps even over his head. That's enough for me to question anything he says.
FWIW, I use 10 AWG Carol cable (Lowes' very best) with Marincos just for good measure--and with big ferrite cores to boot. It'll carry more current continuously than any amp needs that I'll ever own and costs nothing. I own Element Cable cords, too. Nicely made, fat, look good, cheap.
"Why do you need some kind of confirmation, approval, affirmation etc. from some people who are NOT YOU, doing tests on audio systems that are NOT YOURS?"
-- You're not really paying attention to what I'm questioning. I'm questioning whether or not the people who hear these things that cannot be measured are hearing actual differences or what they expect to hear. Why would I question it in my own system, in my own ears? Not because I'm looking for approval or affirmation, it's because I understand that I am not immune to psychological bias. A few here seem to think they are.
"Too put it differently - what prevents you from starting doing "all of the above" right now?"
-- The fact that what I hear, or don't hear, is consistent with what is generally considered possible and what has been measured independently, even in listening tests.
P
I don't mean to wax too philosophical, but why does it really matter whether the cause of a music lover's increased enjoyment is due to altered sound waves or changes in one's psychological factors? If it works, enjoy it!
The distinction will matter to scientists, engineers and marketers, for different reasons.
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
Why it might matter to me is my experience that listening enhancements via components which make significant positive alterations in sound waves but insignificant alterations in psycholgical dynamics provide more long term satisfaction for me than components which make no discernable alterations in sound waves but significant positive alterations in psycholgical dynamics.
Hopefully these tough choices are never necessary but defined priorities make deciding about which gear is best to use easier.
Long term listening will separate out short term effects from extended effects. This applies equally to acoustic and psychological factors.
With quick fixes of either type there can be longer term hangovers. :-)
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
It doesn't matter what you enjoy. I'm sincerely glad that you do. But it matters if it is reported here, by "authorities," as if it were established fact, because it dismisses true standards and replaces them with a subjectivism that has eroded the credibility of audiophiles and audiophile manufacturers and the audiophile press. It has been around now for many years, has taken the rigor out of, and all but banished measurement from product development and audio journalism, leaving us with handsome, expensive kit that too often is out-performed by good "mid-fi." As a result, the lion's share of the progress seems to be taking place in the pro audio market and the high end seems to be doing little more than re-cycling old ideas and applying often misguided analog principles to digital information for old hobbyists who seem to have abandoned the quest for fidelity to a comforting tone. I think it has been very bad for the hobby and the industry and I hate to see it coming into the digital arena. I wish it had stayed with the analog loyalists where it would no longer impede progress.
MHO. YMMV, of course, but frankly, I fail to see how my POV is any more of an "agenda" than the belief that everything makes a difference, even when there is no clear reason to expect it to and instruments many times more sensitive than our ears say it does not.
I'm sure this will stir up a lot of ire, but you asked. With that, I'm growing tired of the angst, and even more weary with a relative few who, while they feel free to repeatedly express their own views, seem to think the expression of mine is an offense to audiophiledom. I think I'll withdraw for now.
Rylands -- There is no cultural or language divide here. The moderator is the person who guides and interacts with the participants during testing, as opposed to the person who designs the methodology or interprets the results. If you can't understand why that person would need to be as blind as the participants in an AB/X study, I recommend Google as a starting point. I suspect a bit of reading will also inform you that AB/X studies are, indeed, a recognized, respected research tool, not a house party or a marketing plan, as you seem to believe. And THAT, by the way, is how I know you're out of your depth here. You may be able to write the book on some other brand of research, but this one is clearly not within your range.
P
I think you place too much faith in "authorities" and "true standards". For me, the watchword is "caveat emptor". In this day and age it is not just business which is corrupted, but other institutions including organized science. In matters audio, I use my own senses and mind to double check all so-called authorities.
I judge the pro-audio market by the quality of recordings that are being produced. The bulk of them are execrable, what with loudness wars and pitch correction, not to mention commercial sound at "live" concerts. No doubt there is good pro equipment, but the same can be said of high end audiophile equipment.
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
"I judge the pro-audio market by the quality of recordings that are being produced."
You judge the quality of the equipment being produced Apogee and K&H by the questionable tastes of the major labels' management? Odd.
P
"You judge the quality of the equipment being produced Apogee and K&H by the questionable tastes of the major labels' management?"
It goes well beyond major labels and management. It goes right to the engineers who buy the pro gear, turn the dials, and produce the c***. These people may be able to hear, but their love for money exceeds their love for music. (If it were otherwise, they would have found a different career.) Many of the Indie labels suffer from the same problem. My presumption is that the equipment is well made for the purpose for which it is used, producing s***t.
There are exceptions, including the high end pro audio companies marketing to engineers and labels making quality classical music recordings.
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
There are a lot of assumptions there, Tony. Damning assumptions about people you don't know. If you are in a position to do what you like, in spite of the desires of your employers and the demands of the market, I congratulate you. Most people don't have that luxury.
If you ever find yourself interested in pro gear, I'd be happy to point you toward a level of excellence that only a few high end companies approach. What you do with it to listen, or to make a living, will be up to you.
P
"There are a lot of assumptions there, Tony. Damning assumptions about people you don't know. If you are in a position to do what you like, in spite of the desires of your employers and the demands of the market, I congratulate you. Most people don't have that luxury."
People who know that they are doing bad things to earn a living for their family have my sympathy. However, this does not excuse their actions, which result from an unfortunate combination of a corrupt culture, a corrupt industry, and their particular circumstances. If these people had been blessed with better circumstances or more strength of character then they would have been able to find a respectable occupation, rather than one that serves a commercial master at the expense of musical art.
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
Wow. I deeply dislike brick-walled masters, but I don't take it nearly that seriously. Perhaps it's because my tastes in music expose me to little of it. I do have a few albums of very good music that have been rendered nearly unlistenable by bad mastering, though, so I sympathize with your POV.
P
Wow. I deeply dislike brick-walled masters, but I don't take it nearly that seriously. Perhaps it's because my tastes in music expose me to little of it. I do have a few albums of very good music that have been rendered nearly unlistenable by bad mastering, though, so I sympathize with your POV.
P
Fortunately I don't listen to pop or rock, so it's no personal loss what has been done to this music. I would have neglected the loudness wars, except that this style of over-processing began to infect some genres of music that I do listen to. This led me to see what I could do, in some cases mastering some albums that would otherwise have been compromised, as well as trying to educate musicians, who are the people who really need to be educated as more and more production goes independent.
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
I've noticed a bit of loudness creeping into some of the music I love as well, but so far it hasn't been the kind of excessive compression that crushes the dynamic range out of so much popular music. Whatever you are doing to push back that tide, I commend you. I think it is turning, but very slowly.
P
What pro DAC do you recommend P ?
I doubt I would recommend a change of DAC at all. Unless you use something colorful, like an NOS DAC or a DAC with a tube output stage, or anything that is attempting to create "analog sound" out of digital to analog conversion, a change of DAC isn't likely to make a worthwhile change in your system's sound. If there is any piece of equipment that you should buy by the numbers, it's a DAC. YMMV. MHO. YADDA YADDA.
P
If it's a physical change in the performance of the system, then it is probably transferable to other systems (though perhaps not audible to other listeners). But if it's purely a psychological change, then it's less likely to be transferable to other listeners.
I know that I'm not going to get anywhere by sticking only to things that have been "proven" in rigorous double blind peer reviewed experiments. But I also don't have the time to waste endlessly throwing spaghetti at the wall to see what sticks. That's a mostly futile exercise, like trying to solve a min/max problem via random walk. So I think it's important to understand the mechanisms affected by the changes we make.
Sounds like you have the engineering mentality. (Me, too.) :-)
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
Switching back and forth between Amarra and ITunes, I can't say I could pick accurately more often than I would have chosen by flipping a coin.
O....M....G
I am otherwise speechless at this admission.
I have a friend with a great system, a beautiful Rives designed room, and the ability to easily hear differences in equipment. He has a recent MacBook and uses Amarra. He doesn't hear any difference between AIFF and Apple Lossless. My main audio pal here in town also has a fine system with a recent MacBook and Amarra. He can hear differences between these files.I have come to the conclusion that we all listen differently and focus on different aspects of the musical event. "What you prefer, you will hear" has some validity. But to totally embrace that philosophy would disregard the differences that actually exist. What is significant to one listener may not be significant to another.
Edits: 02/28/10 02/28/10
Sometimes when I listen to "Sunday At The Village Vanguard" late at night in my listening room, with a good glass of wine in my hand, I can feel the ambiance of the room and locate the other patrons talking softly and clinking their glasses around me; I enter that physical space and wonder if the reproduction of a performance gets much better than that.Other times, when I put on my headphones in the clear light of day, I understand that Scott LaFaro's bass is panned too far to one side, that the microphones must have been too close to really record the ambiance of the room relative to that performance, that the room sounds may have even been captured by a separate mic, that the ambiance is an illusion and that it was my emotions, desire and expectations that translated that extra mic into the palpable space and contents of the Vanguard.
The revelations of the latter experience have not prevented me from repeating, and enjoying, the former. But they prevent me from announcing, with great authority, that the reality of the former "has well been decided" and that "Anyone with a reasonable system has said so."
So I would say this to all lurkers looking for computer audio guidance and to all participants who have not heard differences between bit perfect players, lossless and WAV, USB cables, systems with way too much RAM and processing power vs systems with only more than enough: You're probably right. In fact the existing science and engineering says you are. These things have only "well been decided" by a relative handful of audiophiles, and their vendors, on a handful of internet discussion boards. Don't spend a moment or a nickel chasing these phantoms unless you are sure the joy of the chase alone will be worth the investment.
Your fly in the fantastic ointment,
P
Edits: 02/28/10 02/28/10
Sometimes when I listen to "Sunday At The Village Vanguard" late at night in my listening room, with a good glass of wine in my hand, I can feel the ambiance of the room and locate the other patrons talking softly and clinking their glasses around me; I enter that physical space and wonder if the reproduction of a performance gets much better than that.
Other times, when I put on my headphones in the clear light of day, I understand that Scott LaFaro's bass is panned too far to one side, that the microphones must have been too close to really record the ambiance of the room relative to that performance, that the room sounds may have even been captured by a separate mic, that the ambiance is an illusion and that it was my emotions, desire and expectations that translated that extra mic into the palpable space and contents of the Vanguard.
Headphones don't create a soundstage like stereo speakers do. It's as simple as that. Plus, the hard panning is much easier to tolerate through speakers than headphones. I don't know why you assume the headphone experience is correct and discount your earlier observations when the headphones can't possibly provide the same experience from that recording.
I know the recording well. When played back on a system with good imaging, there is a clear separation between the players (close) and the crowd (distant) and the crowd is captured in stereo.
I don't assume the headphones get it right and understand that they image very differently. What I'm saying is that the headphones reveal the likelihood that the crowd, the bass and the piano all had their own mics, that the ambiance I feel sometimes when listening is a well-constructed illusion, that when I feel as if I'm sitting at a table in the Vanguard, a good bit of that feeling was created in my head, not in the recording..
P
Everything you "hear" from a stereo system is constructed in your head: ambiance, instruments, singers, everything. The reality is that there are two transducers producing pressure waves, your brain does the rest, interpreting the result as a reproduction of a live event. Different systems will make the reproduction more or less convincing, as you found out when comparing headphones to speakers. It's not just your state of mind, the sound waves reaching your ears are different.
Yeah. I get that. The line I was trying to draw was between the many things our minds "hear," to construct the illusion of playback, and the some of the differences we hear, where there should be none, between computers, files, players, etc.
Analogy: drawing a comparison in order to show a similarity in some respect; "the operation of a computer presents and interesting analogy to the working of the brain"; "the models show by analogy how matter is built up"
P
"differences we hear, where there should be none, between computers, files, players, etc."
Come on. If you don't know better, you should. I can see that you don't grasp electronics or computers to any depth, just where does your expertise lie? Actually the question is largely rhetorical because if you actually do understand ANYTHING well, be it a product, process, person..., then you are surely aware that you are aware of many factors affecting it's performance, however it's established, and nuances of it's performance that are likely lost on the casual observer.
With effort instances of computers, files and players can be optimized to produce results sufficiently identical to each to other to obscure identification by a single observer. If the best observer is available or an entire population then it can be extended to the population. Once the maximum error is well below the thermal noise floor then they can be considered identical for the application. Naturally using techniques to reduce the bandwidth will allow further differentiation but that shouldn't be detectable in actual operation.
Pragmatically NO two components are identical off the line (but they both meet specs). No two instances of the same media are identical. No two people are identical and neither are any two environments, even if the difference is only temporal.
The name of the game is to get differences between instances of a product small enough that most people don't care. It's NOT to get them small enough that an astute user can not sense a difference under any condition.
I mentally cringe when I read posters saying that they did a test using two IDENTICAL (fill in the blank)s. One that I recall from years ago was when someone was doing a test and bought two, brand new CD's and unwrapped each one right before conducting the test to insure that they were identical. As you can see from the above, that indicates not a high level of care, but rather an extreme level of incompetence. I stopped right there because anything further would be literally incredible.
I reckon that horse is beat enough. Your 'should' is wishful thinking trying to masquerade as reason.
Regards, Rick
PS: If, as sometimes happens, my computer eats this rather than sending it, the odds that I'll be able to faithfully recreate it are low, very low. However, I can do one of generally the same ilk...
I can see that you don't grasp electronics or computers to any depthRick, that's an outrageous thing to say - you should be ashamed of yourself. The man knows more about engineering than the engineers on the list, more about bits than the programmers on the list, more about psychology than the psychologists on the list (the other one I know of has the good sense to keep quiet).
He's an asset to us all, a calm oasis of common sense in a topsy-turvy world of people who think that a life-time of study counts for something and, outrageously, that what seems is not always what is.
Really - the conceit! Send them up to Marketing right now and we'll tell them a few home truths about who knows what. Dammit! We've paid for big-time Market Research in our day. We've even got clip-boards.
Edits: 03/02/10
Sometimes when I listen to "Sunday At The Village Vanguard" late at night in my listening room, with a good glass of wine in my hand, I can feel the ambiance of the room and . . . wonder if the reproduction of a performance gets much better than that.Which is well put. However, it also serves to illustrate the fatuity of people with a background in "marketing" purporting to conduct "double blind" tests and claiming that their results are, in any sense of the term, "scientific".
I find the Straw Man argument irritating because it reflects intellectual sloppiness at best. Gordon Rankin's claim that there are audible differences between various file formats (despite identical content) has nothing to do with the fact that a good recording is perceived differently according to circumstance.
Other times, when I put on my headphones in the clear light of day, I understand that Scott LaFaro's bass is panned too to one side, that the microphones must have been too close to really record the ambiance of the room relative to that performance, that the room sounds may have even been captured by a separate mic, that the ambiance is an illusion and that it was my emotions, desire and expectations that translated that extra mic into the palpable space and contents of the Vanguard.
Any recording is fostering an illusion but one in which the listener is a willing participant - we spend serious money to persuade competent technicians, the best of whom have more than a touch of the artist themselves, to help us experience such illusions.
Perhaps one reason that the classic Evans recording sounds less than ideal on headphones is because the engineer (from memory, Rudy van Gelder) never intended it to be listened to in that way. In short, the illusion breaks down. That doesn't mean that it wasn't skillfully prepared, just that the conditions for fostering it are not adequate.
Do you not find, for example, that you perceive recordings of musicians you have heard live differently from those you are not directly familiar with? I know I do. I evoke a mental picture of their playing derived from my memory of their performance. Especially if the performance moved me, it enhances the "feel" of the recording.
I'm sure everyone else is much the same. Ditto for pieces of classical music I know from live performance. Listening to music is an active, not a passive, process - a complex mix of psycho-acoustics, memory, personality, cultural background etc etc. Music is perceived differently in company than on one’s own. And so on and so forth.
Simple, linear notions of what is going on when we listen to music do not (as here you correctly imply) work. Do not presume they be can used when it suits you in an argument (more correctly the argument as it's pretty well the only one you make) but discarded when they don't suit you.
Besides, regardless of what you think of Gordon Rankin's claim and noting in passing that he has done something you have not (designed well-regarded audio kit), I do not see what gives you the right to dismiss his points as "Voodoo Science".
Edits: 02/28/10 02/28/10
"I find the Straw Man argument irritating because it reflects intellectual sloppiness at best. Gordon Rankin's claim that there are audible differences between various file formats (despite identical content) has nothing to do with the fact that a good recording is perceived differently according to circumstance."
-- I never meant for it to be any kind of argument, or analogous to Gordon's file formats. It was only meant to illustrate how we can hear what we expect to hear, what we wish to hear, even when something very different is what is there.
"Simple, linear notions of what is going on when we listen to music do not (as here you correctly imply) work. Do not presume they be can used when it suits you in an argument (more correctly the argument as it's pretty well the only one you make) but discarded when they don't suit you."
-- Sorry if my point seems repetitive to you. If it's any consolation, I let pass the opportunity to make it many more times than I actually bother to respond.
"Besides, regardless of what you think of Gordon Rankin's claim and noting in passing that he has done something you have not (designed well-regarded audio kit), I do not see what gives you the right to dismiss his points as "Voodoo Science"."
-- You're right. The voodoo remark was harsh and unnecessary. Besides, it's not science, voodoo or otherwise. It is pure speculation and personal observation. Gordon hears it. Fine. It's when he pretends that its audibility is well-established and implies that those who do not hear it have inadequate systems that he steps way out of line. That's not voodoo, it's nonsense. These personal, undocumented, unsupported "hearings" are the opposite of well-documented, regardless of what products he has brought to market.
By the way, not that my career has any bearing on this conversation, but I have never conducted a double blind study or any other kind of research study. I always commissioned qualified professional research firms to do them.
P
It was only meant to illustrate how we can hear what we expect to hear, what we wish to hear, even when something very different is what is there.
You seem to miss my point. Thanks to the skill of the recording engineer (it wasn't RvG BTW), it is possible to convey - under the right listening conditions - the ambiance of the recording venue. If the conditions aren't right, the illusion is less effective. To say that you are hearing only what you want to hear is IMHO to misunderstand the nature of the listening process and to under-estimate the skill of the recording engineer.
What makes your Sunday morning/headphones percept more "there" (as you put it) than your Saturday night/Rioja one? What leads you to assume that one result is somehow "right" and the other one is mere self-deception?
The brain is not a mirror - perception is an active process. In the visual field, we don't see "images" of things, we see things . The same is true for hearing.
If it's any consolation, I let pass the opportunity to make it many more times than I actually bother to respond.
Not much consolation really because, though you respond to my quip, you ignore the more substantive point that you are looking for a simple "solution" to a complex issue.
I have never conducted a double blind study or any other kind of research study. I always commissioned qualified professional research firms to do them.
I assumed that. Of course "double blind" tests in professional hands are a good market research tool (and professional opinion pollsters are a lot more rigorous than many give them credit for - what their clients do with the results is a different matter).
What I do not accept is that MR industry techniques can be extrapolated to the psychological/perceptual arena. "Audiophiles" can (and do) blabber on about "blind tests" for days at a time but they're still talking nonsense.
You, it seems to me, are one of them - you regularly argue here that "DBTs" performed by any Tom, Dick or Harry in the audio context typically produce more robust psycho-acoustic data than any listening tests. They don't.
Curiously, in this case, you're doing the opposite. You're right to argue that Gordon's wav/lossless "blind test" performed in an unknown manner on unknown subjects at a trade show (!) without statistical analysis of the "results" is not robust and that his listening tests are probably more valid.
It seems to me that you argue that almost any type of "blind test" is superior to a listening test - unless the results challenge your presumptions about, say, file formats. You can't have it both ways.
"You seem to miss my point."-- And you seem to have missed mine. At least we have that in common.
"What makes your Sunday morning/headphones percept more "there" (as you put it) than your Saturday night/Rioja one? What leads you to assume that one result is somehow "right" and the other one is mere self-deception?"
-- Nothing is confirmed, but as I said in the original post, the headphone listening seems to reveal mic placement that points to a creation, not a capturing of that ambient space. A manipulation. Don't make too much of it. It was only meant to illustrate how easily humans can hear what they expect to hear.
"What I do not accept is that MR industry techniques can be extrapolated to the psychological/perceptual arena. "
-- Well, you can refuse to accept it if you like, but if the research doesn't reveal anything actionable about human psychology/perceptions, it serves no purpose. This is why it exists.
"You, it seems to me, are one of them - you regularly argue here that "DBTs" performed by any Tom, Dick or Harry in the audio context typically produce more robust psycho-acoustic data than any listening tests. They don't."
-- Dramatically put, and overstated, but I believe this: If you, or any individual music lover will go to the trouble to test two pieces of gear, files, etc., against each other in a manner that prevents them from seeing which piece is playing when, you will eliminate the potential for psychological bias and get a much more objective evaluation. That's common sense. I also believe that if you did that, you would spend a lot less money in the first place and trade a lot less often in the second. Which might totally miss the point.
"Curiously, in this case, you're doing the opposite. You're right to argue that Gordon's wav/lossless "blind test" performed in an unknown manner on unknown subjects at a trade show (!) without statistical analysis of the "results" is not robust and that his listening tests are probably more valid."
-- I haven't commented on Gordon's DBX testing at all. I've received email notification of its existence, but haven't read it yet, so I'm not at all sure what you're talking about.
P
Edits: 03/01/10 03/01/10
but if the [market] research doesn't reveal anything actionable about human psychology/perceptions, it serves no purpose. This is why it exists.True - but it researches perceptions, not perceptual mechanisms. The difference seems to elude you but I (and thousands of others) get it.
If you, or any individual music lover will go to the trouble to test two pieces of gear, files, etc., against each other in a manner that prevents them from seeing which piece is playing when, you will eliminate the potential for psychological bias and get a much more objective evaluation. That's common sense.
No, you reduce the possibility (only an incurable optimist would say it eliminates it) of one type of psychological "bias". However, unless the experiment is competently designed (a point that eludes many in the audio field), you do so at the expense of introducing other variables which are just as likely to pollute your results.
That's not "common sense", it's established science. Common sense is a jolly sound fellow but the poor chap soon becomes confused in the lab.
I also believe that if you did that, you would spend a lot less money in the first place and trade a lot less often in the second. Which might totally miss the point.
I don't know about missing the point but you certainly miss the facts. My entire audio system costs significantly less than many people's speaker cables: my deck is over 40 years old (I bought it new), my pre-amp nearly 30 (ditto), my speakers about ten (I sold my old ones to a friend when I moved). And so on. When my CD player died, I replaced it with a PC. I don't recall ever "trading in" a piece of audio kit in my life and I don't plan to now.
You perhaps need to extend your "psychological bias" principles to your assessment of strangers: not accepting your cod psychology doesn't make me a spendthrift.
++++
EDIT
If the person conducting the test does not know which example is being played/seen/tasted when, he or she cannot influence the results.
Anyone who designs an experiment so ineptly that he/she cannot be sure that it works properly unless they are willfully uninformed really needs a new job/hobby. The fact that an experimenter is even in a position to interact with the subject typically nullifies results. C'mon . . .
Edits: 03/01/10 03/01/10
Believe if you will that sighted listening tests present no more opportunity for bias than unsighted ones, no matter how informal. Fail to see the common sense in that. Even believe that measures to prevent the necessary human interaction with the participants from influencing the results equals "design(ing) an experiment so ineptly that he/she cannot be sure that it works properly unless they are willfully uninformed." You have only revealed that you don't understand the subject very well. But go back to the beginning of this thread and tell me that you believe, as Gordon said, that the effect of excess digital processing power on analog audio has "well been shown," or whatever that was, and you will have pushed beyond misunderstanding into foolishness.
By the way the "you" wasn't meant to refer to you personally. I'm sorry if I was unclear.
P
Believe if you will that sighted listening tests present no more opportunity for bias than unsighted ones, no matter how informal.
I argued quite the opposite. Making a fetish of the experimenter being "blind" is to clutch at methodological straws. No one is suggesting that the subject in an experiment can safely be "sighted". However, the notion that a competent experiment calls for an "unsighted" experimenter is, to me, risible. The more serious debate is about whether sub-standard experiments are more reliable than informal, subjective listening sessions. I'm far from convinced they are.
The results of a poorly-designed "blind" test are usually useless and have the added drawback of a veneer of objectivity that deceives those who haven't thought about the issue much. I don't know what an "informal" test is: I know only of good tests, bad ones and those that, neither one nor the other, could do with being run again.
Simply because a test is "unsighted" does not mean that it is not subject to a wide range of possibly fatal biases. For example, what order do you play your samples in - does it matter if the "better" sample is played first (so the perception of the "poorer" one is coloured by information present in the better one)? It might do, it might not - you need to test for it and design accordingly. How long do you play the samples for (allowing for what, if memory serves, psychologists used to call "interference" - maybe they still do)? How loud? What may be missed at one volume may be apparent at another. How closely do you need to match volume levels? How to ensure that your kit is even good enough to reveal the differences ( pace the Meyer & Moran fiasco)? How important is subject selection?
Does it matter how often you repeat the same sample? In other words, how random is "random"? Truly random sample selection will lead to sessions where one alternative is played far more often than the other and even to those where one only is played. The pressure on a subject in such sessions to identify some instances as different would be intense - the test scenario introduces a psychological bias of which the experimenter is blissfully unaware by design . It may be "common sense" to be unaware of this possibility but it seems more like poor technique to me.
I wonder if it's even crossed your mind that failing to control any of these variables can render the results useless. Sloppy standards may be quite the thing when deciding between brands of salad dressing, I don't know - but they will let you badly down in this field. No amount of bluster will conceal that.
So, in short, I have considerable sympathy with those who say that it is too difficult to design reliable experimental tests and that, absent the resources, it is better to eschew sloppy experiments and look to subjective rankings instead. They have serious flaws as well as benefits - but at least we know what the flaws are.
You have only revealed that you don't understand the subject very well.
That's the second or third time you've said that in our exchanges. With respect, it's insolent. I might well be poor on experimental technique - but how would you know?
Tell me that you believe, as Gordon said, that the effect of excess digital processing power on analog audio has "well been shown," or whatever that was, and you will have pushed beyond misunderstanding into foolishness.
Why do you always change the subject? I never suggested anything of the sort, have already dismissed GR's tests and have argued often enough the opposite point.
"That's the second or third time you've said that in our exchanges. With respect, it's insolent. I might well be poor on experimental technique - but how would you know?"
You seem to be saying that blinding the moderator to eliminate his or her possible influence on the participants (AB/X vs AB) is somehow indicative of bad methodology...
"However, the notion that a competent experiment calls for an "unsighted" experimenter is, to me, risible."
...and I'm sorry that you find it insolent, but that means that you do not understand the kind of testing being discussed.
P
*** You're right to argue that Gordon's wav/lossless "blind test" performed in an unknown manner on unknown subjects at a trade show (!) without statistical analysis of the "results" is not robust and that his listening tests are probably more valid. ***
You have hit the nail on the head - what Gordon described is not a statistically valid test. It wasn't "double blind" (which would imply neither the observer nor the experimenter knew what is being tested), and it wasn't ABX, simply AB, hence subject to all sorts of biases.
What I found amusing was the implication that *if* Gordon was right (that is, if differences between formats were audible and that CPU processing capacity was a factor) *then* it indicates that his products are not working effectively (because async USB is *supposed* to isolate such differences away from the DAC). Not sure he intended to convey that implication to his readers.
Async does not isolate electrical noise from the computer that is passed down the USB cable. All it does is reduce the jitter between the computer and the DAC. ASYNC is not a magical interface that makes everything in the computer no longer matter. Perhaps you should try some ASYNC DACs on your system and get some first hand experience.Please don't respond to me in Japanese :)
Edits: 03/01/10
Mercman, I do have an async USB DAC in my system and I am well aware that it is not perfect.
I am not sure what you mean by "isolate electrical noise from the computer that is passed down the USB cable".
I have done electrical engineering and have designed my own circuits but I'm still scratching my head on this one.
If you are completely reconstructing the signal timing, which is what an async USB DAC is supposed to do, then any noise from the input should be isolated from the DAC. Unless of course you were such a poor designer that the input signal is causing power rail modulations.
Since you mentioned distortion measurements I'm curious what tools you use...If you don't mind my asking and going OT for a moment. I'd like to do measurements and can't really justify an analog distortion analyzer but would certainly look into low cost PC software/soundcard solutions.
I guess I better leave this to the engineers to explain. But there is high frequency noise generated by the switching power supply that is not related to jitter. But you know all of this.Thanks
Edits: 03/01/10 03/01/10
You mean the switching frequency (generally 50kHz-1MHz)?
That shouldn't affect even a synchronous signal - gets filtered out.
Or are you talking about EMI/RFI? Yes, that could affect the DAC, but Gordon was advocating a higher powered CPU, which generates *more* noise than a low powered one.
A higher CPU doesn't necessarily generate more EMI/RFI. Famk has previously pointed out "The effect depends on many factors including chip design, interaction, board design, power supply decoupling, audio section design etc etc."
Christine, my expereince with my 3 macs support Gordon's findings. If I can't trust my hearing, I better find another hobby.
Of course it depends a lot of factors. That's stating the obvious.
However, higher thermal power plus higher clock frequency = higher RFI. Can't walk away from that one.
But it is also true that modern CPUs automatically underclock themselves when idling - definitely true for Apples (controlled by the AppleIntelCPUPowerManagement.kext kernel extension).
In the end, we don't know unless we measure it. And even then, the impact depends on a whole host of other things.
I don't think Gordon's point was based on RFI - previously he has posted that he believed the differences were due to CPU "spikes" which are more pronounced for slower processors which he claims affects the THD.
Now, that is *exactly* the sort of effect that a good async USB design is supposed to isolate against. I have measured my DAC on slow and fast systems, and can confirm there is no measurable change in THD. Then again, I don't notice any CPU "spikes" on my systems ...
That's why I pointed it's ironic that if what he claims is true, then it does imply that the async USB design is ineffective in preventing exactly the sort of issue it was designed to protect against.
Fmak has previously pointed out "The effect depends on many factors . . .
Fair comment - but not exactly right IIRC. The argument at that time was about whether under-clocking reduced RFI, not about changing to more powerful processors. Besides, some of us felt it was never quite resolved.
Dave,
What if I slip you a $50 ? Would you then agree with me? :)
Steve
What if I slip you a $50 ?
Come, come, I have my principles.
$75 or no deal.
D
PS Or, as Groucho Marx put it:
"You don't like my principles? Well, I have others."
C'mon guys, a fair exchange would be a brand new MacBook, surely? :-)
Slip me the latest greatest model, and I'll happily agree yes, the faster and more powerful, the better the music sounds to me :-)
You're easy to please!!
Actually, I'm much cheaper than that.
A good dinner, plus wine, and I'll probably agree to anything!!!
Oops - probably shouldn't have revealed that tidbit. Okay okay, I need at a minimum a diamond-studded iPhone!!!
When you combine async transmission with optical isolation it's pretty hard to see any mechanism for computer noise to affect the DAC except through the power supplies.
I am aware of the QB-9 design. I just discussed one example of something that influences the sound. I support Gordon's views when dealing with OSX.
If noise is really the issue, then I have trouble understanding the logic behind some of Gordon's recommendations. Let's take the "headroom" argument for example. If more computing power = more headroom = better sound, why stop at a Mac Mini? The Mini is also a curious choice when you consider RFI/EMI issues because everything is packed closely together and the GPU is on the same board. I'd think there's far more opportunity for RFI to pollute the USB connection with such packaging. Ditto for a laptop. If minimizing noise over the USB interface is important, wouldn't it be better to take USB off a daughter card installed in a regular desktop case and run the computer headless controlled via Ethernet?
Even the choice of OS X (or Windows in Cics case) is curious. If having other non-audio processing going on impairs audio playback, wouldn't it be better to use a stripped down embedded Linux that only plays audio?
Being skeptical, I often wonder whether Gordon's choice of Mac Mini + OS X is primarily aesthetic.
It wasn't "double blind" (which would imply neither the observer nor the experimenter knew what is being tested), and it wasn't ABX, simply AB, hence subject to all sorts of biases.
What is the procedural merit of an experimenter not knowing what he/she is doing?
I have to confess I'm not even sure (heck, probably haven't a clue) what an ABX test is and that reading up on the technique generally leaves me more confused than I was before I started. "AB vs ABX" strikes me as a phoney distinction between two equally suspect procedures.
I'd like to know the rationale for the apparent assumption that perceptible differences can be detected reliably using only one sampling procedure. What little I've read on the subject seems also to assume that subject populations and the like do not matter.
And so on - but I'm happy to be proven wrong.
AB=you compare A en B and you know that you are listening to A or B
ABX= you listen to A, you listen to B and now a third party (might be Foobar ABX comparator) randomly plays A or B. You score without knowing if it is A or B playing.
After 10 or so trials you compare your score with the real score and check if you are above change level.
Compared with DBT this is probably SBT
What is the procedural merit of an experimenter not knowing what he/she is doing?
None of course, in all experiments the experimenter makes the design, the experimental setup and is supposed to know what he is doing.
In DBT, the experimenter knows, the participants and the raters (often patients and doctors) don’t.
A proper conducted ABX is in essence a unsighted test. Of course the results are not conclusive, it claims just one but not unimportant thing, removing the bias from the experiment.
It says nothing about the conditions (program material, gear, room, etc)
The Well Tempered Computer
In all experiments the experimenter makes the design, the experimental setup and is supposed to know what he is doing.
Quite - the notion that an experimenter has to be ignorant of what he/she is doing to "prevent bias" is so fatuous it is not even worth discussing. (I can see why there is a case for doing it in market research but that's a different matter.)
In the audio sphere, many of those who advocate "DBT" methodologies seem each to have their own idea of what the optimum procedure is but are reluctant to tell you what it is, apparently rely on the naive assumption that essentially the same test design is adequate for every parameter you care to investigate and definitely have a thin skin if you question their ideas.
Almost invariably, it turns out that they have not conducted tests of the type on which they claim expertise and cannot even point you to competent reports of examples conducted on the lines they recommend. (If anyone can, I'd greatly appreciate it.)
It's a mess - I don't blame manufacturers and designers for trusting their ears rather than the aggressive meanderings of experimental wannabees.
You're confusing experimenter with moderator. Further evidence that you are out of your depth.
P
Further evidence that you are out of your depth.
Can you explain what, in the context of a psychological experiment (or come to that any scientific experiment), a "moderator" is. I do not know what you mean by the term.
Trust me, I'm not out of my depth here (nor am I clear how you would know if I was) but it may be that there are cultural/semantic differences at play.
and just to add, the main reason for double blind is so that the experimenter does not (knowingly or unknowingly) bias the results.
A classic example of bias is the following: I am at an audio trade show and I tell an audience of guinea pigs (sorry, audiophiles) that I have two systems that I want to see if they can spot the difference.
Well, simply by me making that statement, I have preconditioned the audience to expect differences. This will encourage an audience member to say there was a difference even when there isn't, and to guess which is which.
I'm not saying this is what Gordon did, simply illustrating that it is so easy to get the result that you were aiming for. The percentage figures he gave are meaningless without confidence levels attached to them, and frankly given the testing conditions and the sample size are not inconsistent with pure speculation on the part of the audience.
Simply by me making that statement, I have preconditioned the audience to expect differences.This is true and you are right about the need for stats - but the scenario you describe is not by any stretch of the imagination an experiment, it's a trade-show participation game. Harmless, good fun and possibly informative in a loose, back-of-the-envelope sort of way that no-one with a modicum of scientific training would take too seriously.
Inevitably, as soon as you ask someone to participate in an experiment, you confess that you are looking for something. If you weren't, you wouldn't be doing the damn thing in the first place and you certainly wouldn't be funded for it.
So, you address the problem with measures that have stood the test of time in a myriad of fields - a prior and clearly-defined null hypothesis, appropriate controls and defined control groups. You do NOT do it by losing control of your own experiment. If your own antics prejudice the results, the experiment is either badly designed or poorly conducted - and probably both.
Must dash - I hear there's a real wheeze on Stand 413 - if you do their cable-shootout test and give the right answer, you get a free drink.
Edits: 03/02/10
*** You do NOT do it by losing control of your own experiment. If your own antics prejudice the results, ***
It's not really about losing control, it's about ensuring that your personal biases and knowledge do not influence the results.
A classic example of this is "psychic" experiments where they found out that subjects were getting the correct answer simply by reading the body language of the experimenter.
But it is also possible that you can do everything right (use all the right buzzwords and even apply them correctly) and still get it wrong. An example of this is that infamous study which "proved" by exhaustive double blind testing that people can't differentiate between SA-CD and DVD-Audio.
Problem was, the researchers didn't take into account that it takes time for someone to get used to the differences. And hearing acuity can be improved with training. An average person would find it difficult to distinguish between MP3 and CD, and yet people can train themselves to hear the differences. The study ignored the fact that there were at least two subjects they tested that were able to spot the differences consistently - they just brushed those subjects aside rather than investigate the reasons why these two can tell the difference and others couldn't.
This shows how powerful experimenter bias is in clouding thinking. The experimenters wanted to believe there was *no* difference, so they deliberately interpreted the results to fit their prejudice (*Most* people can't hear differences, therefore there *are* no differences).
See you at stand 413 - except my ability to distinguish differences is so poor I may need to steal a few sips from you!
It's not really about losing control, it's about ensuring that your personal biases and knowledge do not influence the results.An experimenter who cannot control "personal bias" in tests of this sort is out of his/her depth - it's undergraduate stuff. The fact that some who perform ever-so-scientific tests in the audio field are out of their depth is sad but true.
A classic example of this is "psychic" experiments where they found out that subjects were getting the correct answer simply by reading the body language of the experimenter.
The story is often told the other way round - it's the "psychic" who reads the body language of the subject :> ) Whatever, even if serious "psychic" research (so help me, there's a Chair of Parapsychology at Edinburgh University) is, for most of us, an oxymoron, competent researchers first addressed the issue 100-odd years ago when there was a craze for things "spiritual" in Britain and loads of sensible folk keen to debunk it.
But it is also possible that you can do everything right (use all the right buzzwords and even apply them correctly) and still get it wrong. An example of this is that infamous study which "proved" by exhaustive double blind testing that people can't differentiate between SA-CD and DVD-Audio.
The Meyer and Moran paper (M&M - the one that "proved" we can't differentiate between RBDC and SACD) did almost nothing right: it was deeply flawed from the off. See e.g. these posts:
see: http://db.audioasylum.com/cgi/m.mpl?forum=pcaudio&n=57852
and:
http://db.audioasylum.com/cgi/m.mpl?forum=pcaudio&n=57904
from July last year where I try to explain why. (Sorry about all those ' thingies - they turned up after a recent AA archive revamp.)
(Ironically, I was also debating with PP who resorted as readily then as now to ad hominem abuse and a mix of sarcasm and Google.)
Problem was, the researchers didn't take into account that it takes time for someone to get used to the differences. And hearing acuity can be
improved with training.M&M was flawed on several fronts, not just on "training" issues (though I'm sure you're right to raise them). The authors' competence in other fields didn't protect them from schoolboy howlers in this one.
An average person would find it difficult to distinguish between MP3 and CD, and yet people can train themselves to hear the differences. The study ignored the fact that there were at least two subjects they tested that were able to spot the differences consistently - they just brushed those subjects aside rather than investigate the reasons why these two can tell the difference and others couldn't.
Assuming we're talking of the same paper, M&M didn't get five per cent significance for any subjects so I'd hesitate to accuse them of brushing aside awkward results.
On a personal note, I find that mp3 quality varies from execrable to acceptable. I have some mp3-sourced recordings that sound really quite good but others, made from what I know to be a good source (as I have the CD), I simply cannot listen to. Whether that's inherent in the process, down to bad engineering, a bit of both or something else altogether, I can't say.
I suspect that the mp3 v CD thing would actually prove tricky to test properly because you have two variables at play - quality differences within and between formats, not to mention vested interests.
This shows how powerful experimenter bias is in clouding thinking. The experimenters wanted to believe there was *no* difference, so they deliberately interpreted the results to fit their prejudice.
Experimenter bias is powerful in clouding the thinking of incompetent experimenters only. Any half-way decent design addresses it early doors. I read M&M several times before writing the above critique and have just re-read it. I find no grounds for suggesting that the authors "brushed aside" any results and I don't think they fairly can be accused of "deliberately interpreting" them to suit preconceptions. They genuinely got them - but they were always going to get them because of flaws in the experiment's design.
Inevitably, those who wanted to believe the results did so without reading the paper with much care. Now those folk were biased . . .
Edits: 03/03/10
*** The story is often told the other way round - it's the "psychic" who reads the body language of the subject :> ) ***Well, it's the subject's "psychic" ability that was being tested. The experimenter knew what the answers were, and was subconsciously conveying the answers through body language to "successful" subjects.
The M&M paper is interesting, but wasn't the paper I was thinking of.
My memory is terrible these days, and it may well have been the paper, I'll have to look around to see if I can still find it.
I agree that the M&M paper is kind of ... "interesting" reading (sarcasm hat on).
MP3 quality varies by encoder as well as bit depth. A proper MP3 vs lossless test will require you to encode everything yourself using a known encoder, rather than casual comparisons of stuff downloaded from the internet. I personally find great difficulty in distinguishing between MP3 and CD at bitrates above 240 kbps, below that yes it is possible.
It's possible to train the ear to recognise lossy artefacts - for MP3 just listen very carefully to the high frequencies for signs of "phasing." For Ogg Vorbis it's ringing, for WMA it's an increase in low level noise and some "flattening" of the dynamics. As you up the bitrates, these artefacts become less and less and eventually there are no obvious clues.
Edits: 03/03/10
"The experimenter knew what the answers were, and was subconsciously conveying the answers through body language to "successful" subjects."
Also, if you have multiple subjects taking a test in the room at the same time, they can be potentially influenced by each other's body language. As a result, their perceptions can not be considered statistically independent, which means that the statistical power of an experiment is substantially reduced (depending on the numbers listening at once).
"The M&M paper is interesting, but wasn't the paper I was thinking of."
Check the attached link. Perhaps this was the paper you were trying to remember.
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
.
Also, if you have multiple subjects taking a test in the room at the same time, they can be potentially influenced by each other's body language.
And if they're suspended by their ankles from an elastic chord over a vat of boiling acid, they find it hard to concentrate on the quality of the mp3 sample under test, even in isolation in a darkened room. This may explain why neither scenario is regularly reported in the literature.
Meanwhile, thanks for the link to the AES paper, which I look forward to reading. They seem to have eschewed the acid bath . . . how dull.
D
"What is the procedural merit of an experimenter not knowing what he/she is doing?"
If the person conducting the test/interfacing with the participants does not know which example is being played/seen/tasted when, he or she has no opportunity to influence the results.
P
"What is the procedural merit of an experimenter not knowing what he/she is doing?"
If the person conducting the test does not know which example is being played/seen/tasted when, he or she cannot influence the results.
P
What would teh minimum processor power be needed to do loseless files?
navman
Gang,
Here's the deal... It has well been decided by many that lossless does not sound as good as flat PCM files. Anyone with a reasonable system has said so.
That being said... it has also been proven that the more power you computer has, i.e. more memory, SSD system drives, speed etc... will cut that difference down.
The weird thing is that both outputs are bit true and equal.
WHY? who knows throw this one in with why do USB cables sound different.
Thanks
Gordon
J. Gordon Rankin
> It has well been decided by many that lossless does not sound
> as good as flat PCM files.
> Anyone with a reasonable system has said so.
This is only true if you rule out the reports from people who say they do not hear a difference. There have been a number of such posts on this forum.
Bill
Gordon,
Where and by whom has this "well been decided?" Please provide links to the science and engineering indicating even the possibility, the measurements, the independent blind listening tests, that have been deciding well that not only do PCM files sound different from lossless, but that if you play them back on a system that has way more processing power than is required to play audio files instead of one that simply has quite a bit more processing power than is required to play audio files, that we will been deciding that they sound even better.
P
Gang,
We did double blind testing in the following way;
1) 2 computers MacBook Pro and MacBook (MacBook Air at last RMAF) both dual boot Vista Ultimate/OSX with J River and iTunes (we did not use amarra).
2) We would play a WAV and a FLAC of the same song. We would play an ALAC and AIFF. 10 songs total... most of the time like 30-60 seconds these would be randomly mixed (i.e. sometimes FLAT PCM first [AIFF/WAV] sometimes lossless first). Each person was given paper to record the scores.
Conclusion...
a) 93% could tell the difference with the slower MacBook/Air. This is over 50 people now at more than 4 shows.
b) Using a faster machine in the same test brought that number down to 58%.
Remember gang we are using pretty pricey systems. Last years RMAF the system retail was over $70K
It's like this... someone asked me today when the Proton would be taken to 24/192. I said probably never.... as you really would not be able to hear any difference when going from 96 to 192. So why bother....
If you have an average system then none of this applies.
Hey do your own tests... all of these files were converted to and from and back and compared. They are bit identical...
An interesting note... I did a 1KHz sine wave in two formats ALAC/AIFF as I was on a mac. I then ran every freaken hog application (PS CS4... etc) I could find on my machine. The THD rose up for the ALAC at a much higher rate than the AIFF.
I am trying to work on a timing test. But for some reason my WaveCrest will not seem to lock onto a 1KHz square wave... I may have to try running this at 96K or 192K and then run a 10KHz square wave but I think timing is also to blame.
Either way it seems well evident that the processor performance has a significant determination of decoding on the fly which is a huge component of lossless files.
Thanks
Gordon
J. Gordon Rankin
Hi Gordon,
You recommend to use faster computers as transports right? So could you tell me why? Is there a techical explanation or is this just the result of the blind test?
Thanks
korhan
Gordon,
So... Not clear what you're saying.
There are 2 obvious test scenarios here, computer speed "slow" vs. "fast" and WAV vs. FLAC/ALAC. Given any one computer - take the faster Mac Pro, are you saying that most of the 50 people could determine difference between WAV and FLAC? What percentage accuracy?
If this is true, why aren't the objectivist obsessed folks on Hydrogen Audio raising hell?
Personally, I can't tell a difference between between FLAC and WAV. Decoding a FLAC file takes barely any CPU power, can be tagged, allows for lots of compression especially classical pieces, which helps speed up backups; essential for big music libraries.
Here's another one: do you think there's a difference between FLAC leve 1 vs. level 8 compression? Does the noise floor proportionately increase?
"An interesting note... I did a 1KHz sine wave in two formats ALAC/AIFF as I was on a mac. I then ran every freaken hog application (PS CS4... etc) I could find on my machine. The THD rose up for the ALAC at a much higher rate than the AIFF."
What DAC did you use? How did you measure distortion? What were the distortion readings with and without the extra processes running? Do you have scope traces and/or spectra of these cases?
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
Phelonious, I agree with you.
It has not been "well decided". It happens to some listeners with some equipment. There are three schools of thought on this matter:
1. Those who hear differences do so by superior equipment and hearing acuity.
2. Those who hear differences are subject to quirks and defects in their equipment and setup.
3. Those who hear differences are victims of subtle psychological effects.
There is no evidence as to which group of people is correct. Pragmatically, if you hear a difference then go with whatever you prefer. (I've not heard anyone report that lossless compression sounds better, but it's conceivable that could be the case with some gear.) If there were scientific instruments and measurement procedures that resolve this dispute, then I expect that within a year or so we would see products that were suitably immune to transport issues.
With my software (cPlay) the FLAC decoding takes place in bursts, generally at the time a track starts up before the music begins. I do not hear any differences with this setup. When I run audio editing and restoration programs (Soundforge Pro 10 and Izotope RX) I use WAV files.
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
With hard drive cost at an all time low (today I saw a 2TB drive for $135 after rebate), why use compression? If you have a CD collection of 1000 discs, that's around 600GB in the .wav or .aif format. The 1TB drives are going for about $70 these days (mostly after rebate), so there's your collection, uncompressed, on one hard drive. Buy a second one for backup and you're only at $140. Putting that into perspective, some people spend more $ on a single cable.
And even if you have a budding High Resolution collection, just buy two 2TB drives.
AIFF files support tags, but WAV files don't. If AIFF were more widely supported outside of the MAC platform I'd probably rip to it. I think embedded tags make it much easier for a music library to be shared by a variety of media players, which is why I don't consider WAV to be a suitable file format.
Alan
Now will have to re-rip all my files to Wav? Does wav do ID3 tags?
navman
and the reason I would never doom my music collection to wav no matter how cheap, even free, hard drives are...
In the future, if you ever need your music in any other file format, you would turn your wav files to XYZ and find you have no tags and no way to sort, search, identify your music.
My 800 MHz (that's 0.8 GHz) VIA CPU will happily decode FLAC 192kHz 24 bit, and play them back flawlessly over a 10Mbps Ethernet connection.
The Atom 1.6GHz CPU running on netbooks should be 3-4 times faster than the CPU I'm using.
I'm with Christine here.Using a 1.6G Atom on my Windows Home Server as source to my Squeezebox/Transporter system with absolutely no skips or issues downconverting from 24/192 to 24/96 or 24/48.
This should be a much more processor intensive 3-step process than just playing FLAC: 24/192 decode --> SOX to downsample --> Encode back to FLAC; all in realtime.
In daily usage, it's obvious that the Atom is a slow machine but for single primary task of audio processing like above without big demands like complex plugins, it's not an issue IMO. Maybe what people describe with FLAC vs. AIFF/WAV is due to the soundcard/chipset being affected by RFI from the processor doing its thing... If this is the case, that's pretty poor design!
Edits: 02/27/10
Thanks to all who have chipped in.
Plan is to have the Netbook connect via HagUSB to a Non oversampling DAC or even my old ART DI/O to a headphone amp to either Grados or Senns depending on which amp I go for. Later I'll start plugging it into my main systems and will compare it with standalone CD players.
navman
What would the minimum processor power be needed to do lossless files?
Using cMP^2, I've been playing flac-format files (mix of 44.1 & 48 KHz) on a Fit-PC2 running a 1.1 GHz single-core Atom processor day in and day out for several months now. If it's not up to the job, someone forgot to tell it.
I use an 160GB asus eeePC and it works quite nice. My son wonders why I have such a large iPod! I'm still working on my "system" which will include squeezebox but for now the netbook works fine and was quite cheap on eBay
My squeezebox has stopped being able to connect to the server, so have ditched that.
navman
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