Will digital CD audio differ from player to player?

KeithH

Lead Actor
Senior HTF Member
Joined
Mar 28, 2000
Messages
9,413
Marc, I think the jitter device involves a ouija board as a key component. As I recall, all the developers of the jitter device were drugged and had kidneys removed. At least that's what a friend of a friend told me.
 

Lee Scoggins

Producer
Senior HTF Member
Joined
Aug 30, 2001
Messages
6,395
Location
Atlanta, Georgia
Real Name
Lee
So, engineers discovered that jitter made a difference. How did they discover this? Did it involve applying the scientific method, or if not, what took its place? Is a "jitter analyzer" a scientific instrument, or is it something else, like a religious ritual or a magic 8-ball?
Actually audiophiles discovered it made a difference and the engineers later caught on.

Nevertheless, the point was that science could not explain everything (and still can't) about CD players at the time.

How jitter was discovered and what scientific instruments were used is not particularly relevent.

I guess one could say that scientific tools were used to discover that science did not explain all the audio differences.

Kind of a suitable punishment for the engineering community.

Very rich irony.
 

Lewis Besze

Cinematographer
Senior HTF Member
Joined
Jul 28, 1999
Messages
3,134
Wrong as usual!
The fact that you don't understand simple things,are your problem, and you just gonna have to deal with them!
Good luck to you!
 

ManW_TheUncool

Lead Actor
Senior HTF Member
Joined
Aug 18, 2001
Messages
6,714
Location
The BK
Real Name
ManW
Seems to me you guys are both wrong about "burden of proof". If you want to convince the other side of something (whatever it is), the "burden of proof" is on your side. Period. You can argue about "proof beyond a reasonable doubt", but it's not clear to me (in this thread anyway) that either side did that.

And why is it so hard to believe that current scientific research, instruments, measurements, observations, etc., cannot necessarily prove or disprove this audibility of jitters?? NOTE: I am not saying that this is factual, but rather, "why is it so hard to believe" because as far as I can tell, extremely few, if any of you, have actually done the scientific work to prove or disprove such.

Conversely, the same can be said of the other side of the debate.

Given all that, I do feel that the arguments submitted by the "jitter is appreciably audible" side to be less credible than the naysayers' side although not necessarily by a large degree. I think good DBTs should be done to help settle the debate. All the people w/ the "golden ears" should take the DBTs in addition to a statistically valid sample size of the "regular" folk (and accounting for hearing ability amongs the "regular" folk).

Can somebody point me to such scientifically/statistically sound proofs through DBTs? That would help since I didn't notice any links for such from the "not appreciably audible" side.

_Man_
 

Asim

Stunt Coordinator
Joined
Jan 6, 2003
Messages
78
Guys, you can't leave this thread, at least i hope you won't! it is because of people like you who keep newbies like me who can get caught in the hype to lose sight of the science behind everything audio. couple of things (sorry i can't remember who exactly quoted/said what, and am not sure how to get all of them in here anyhow). I apologize if some of this seems incoherent, but i am analyzing eye movement data in one window and typing this in another:

1) Ian, etc. thanks for putting forth your positions. I agree about DBT tests being a rigorous standard, but even in that kind of testing, in my studies (as a Hearing Neuroscience student) we have been taught that even in strict testing paradigms like DBT, personal fears, values, internal standards, etc., can come into play even then and affect decision making. But that being said, given the other objective mechanisms (or lack thereof), this is perhaps the best scientific way that audio phenom can be judged, especially since there is a whole industry poised to make $$ if results are misinterpreted. I certainly wouldn't believe much from white papers anymore (i think the quality of work done like in AT&T labs, IBM, in the mid-20th century was good stuff though). As a medical student, it is amazing to me how many patients i have seen that feel better as soon as i have prescribed meds to them or done something they think was a "cure" when all i did was examine them. Placebo effect/internal expectations are definitely a huge thing when judging something objectively. Much of medical treatment has been based on anecdotal evidence when rigorous tests have been done (evidence-based medicine with DBT, rigorous trials, etc) a lot of it has been thrown out and practices changed.

2) Lee, while you may be knowledgable in your field as a recording artist, i think in terms of arguing your points logically, (dont take this personally) you have not done a very good job of convincing me. Now of course i am biased in that i am also a scientist/engineer and that my day to day activities involve the hypothesis/proof mantra on a daily basis. As i said previously, the only real proof you can convincingly use are published or at least peer-reviewed papers in which authors have disclosed their financial ties, etc (this is standard in medical/bio/other science journals, especially when drugs are involved) - not anecdotal advice or other such "hoopla." I recently read an article where John Dunlavy himself questioned why more audio CEOs/engineers don't submit themselves for DBT - why they do not leaves me suspect. To be honest, this whole argument reminds me of one of my favorite books, Atlas Shrugged. The people who are "big-hearted" keep putting forth all these arguments against science, etc., but when asked to come up with cold, hard facts, they could not and relied on twisting logic/introducing other (off)topics to further their arguments. And, when those same people were asked to give up their luxuries, etc., and live like the "common man," how many of them actually did that (granted that this was a book)?

3) I actually wish that more people here (and in life in general) speak up and share their opinions (hopefully based on some factual evidence if the necessity is there). I don't remember which one of you said this, but to paraphrase, you were talking about all this mumbo-jumbo and that you talk about "other manufacturers [which you won't name]" out there. WHY NOT MENTION THESE COMPANIES??? Are you afraid of getting sued? Please enlighten or at least bring forth knowledge to the rest of us if we have not been so lucky to arrive at that same point ourselves - isn't that the purpose of this forum? This i guess is a big pet peeve of mine, and it is too bad that i see it here and other discussions, especially with audio. BE UPFRONT. I think MUCH IS LOST with reading in between the lines (perhaps i am just dumb (maybe that's why i didnt like poetry when i was a kid), who knows). Also, those that are "science-based" what equipment do you own? I think this effectively puts your money where your mouth is and would help "teach" others the level of spenditure with good reproduction of sound without hyperinflated $$$ donation.

4) whoever coined the "lunatic fringe" phrase, what had me rolling!


So, am i biased here? yes, of course i am. I am hoping the science wins so my mind will stop perceiving a $1600 CDP will be better than my 2nd hand $100 one. On a side note, i once had a salesman tell me (about 10 years ago) at a hifi place when i asked him a question about CD players..."well you might not understand this, but this uses what they call Riemann sums to produce the sound" to which i replied "do you know what a Riemann sum actually is?" He responded "well its some new math they just came up with." Trying hard not to laugh my @$$ off in front of him, I quickly walked out of the store. If that would happen to me today, i would probably have asked him to show me on paper, at which point after he failed to do so, i would in turn show him and make him feel like a true idiot!
 

Lee Scoggins

Producer
Senior HTF Member
Joined
Aug 30, 2001
Messages
6,395
Location
Atlanta, Georgia
Real Name
Lee
On a side note, i once had a salesman tell me (about 10 years ago) at a hifi place when i asked him a question about CD players
Earlier you fault my logic (which by the way was good enough to secure a top job in business strategy) and then make an argument using a story about some idiot audio salesman. Does this really support the notion of a "lunatic fringe"? NO.

There is a lunatic fringe (for scientific types who can't see beyond their oscilloscopes) and those people are doing amazing things by having an open mind, a thirst for exploration and better sound, still a love of some science where valid, and an ability to make things happen. These people are music lovers, circuit designers, and recording engineers. They deserve better than a drive-by shooting rooted in the fact that most engineers/objectivists cannot accept the following simple fact:

Science cannot measure an entire audio experience.
 

Jun-Dai Bates

Stunt Coordinator
Joined
Aug 16, 1999
Messages
148
Science cannot measure an entire audio experience.
Science doesn't do anything in and of itself. Scientists cannot measure an entire audio experience, but they can measure a lot more of it than anyone else.

Also, Lee, I suggest you look up "Subjectivism" and "Objectivism" in the dictionary. Your definitions are a little off, and I doubt that you would really consider yourself a subjectivist, because that would mean that you don't really hold scientific knowledge to be valid, but rather that you only hold your perceptions to be valid, and that they are only valid to you. Not that you're an objectivist either.

Anyhow, it may be that the sound quality differs from one transport to another in an audible manner, but there has to be another explanation outside of sub-nanosecond jitter. If the digital format put out by the CD is different from the format put out through the digital output of the player (I imagine it is, since it uses a stream of data), perhaps there is something in that processing that might vary from player to player.

As for jitter, if there is ECC in the signal coming out of the CD player, then there must be processing on the receiving side of the DAC or the unit containing the DAC, which would mean sending a different signal to the actual piece that produces the analog signal, which should eliminate any jitter that comes out of the CD player. Additionally, because the audio is processed in individual frames (16-bit frames, 24-bit frames, etc.), any variance in the timing of the bits before the frame is taken from the data stream should be eliminated. Of course, my knowledge of how DACs work is limited, but no one has satisfactorily addressed this paradox here.

But my main point is this: any slight change in the timbre of the audio due to sub-nanosecond jitter would be overwhelmed by timbre-changes caused by a 1-degree difference in the temperature, the presence of a small animal in the room, the movement of dust on your speaker, etc. Night and Day differences should be out of the question, as far as the objective world is concerned anyways. Inside the subjective world, any number of things can affect the perception of sound.

John Royster has taken a limited single-blind test, and that was enough to convince him that there is a difference. If I had taken that test and passed it (and heard night/day differences in the transports) I probably would be convinced as well--perceiving differences for oneself can be incredibly convincing. But it proves nothing. If you have a thorough understanding of the way the human ear works, and of the way sound waves work, and of the way DACs work, then a theory can be developed (and then proven through means which might include DBTs, but would not be limited to them).

Even if John Royster was hearing an *actual* difference in quality that was occuring from the difference between transports, that doesn't mean that jitter is the best explanation. If I had come out of such a test believing that there was a discernable difference between the transports, I would look for other differences before I would consider jitter. In fact, the first thing I would try to do would be to analyze the data being fed from the transport--are they in fact the same 1s and 0s? Until I had answered that question, jitter--especially sub-nanosecond jitter--would have to wait.

John Royster, I suggest you try something else: if there is no feasible way to analyze the 1s and 0s coming from your transport, we can try to determine the effect of jitter another way. Do another test, but with the same transport. Get a good S/PDIF cable between your transport and CD player. Then buy a 20-foot long cable. Cut the long cable into about 10 pieces, and put them back together again with electrical tape. Step on it a few times, etc. Then do a blind test with your wife at the helm, trying to judge the difference between the cables. If you can't hear the difference between the two, then there is probably a better explanation for the difference between transports. Of course this isn't a matter of proving things, but simply a matter of convincing yourself.

But I am speaking of an objective world. A world where truth can be best understood (but never fully understood) through the scientific process. If you are a subjectivist, then you either believe that the objective world doesn't exist, or that it doesn't matter, because it is entirely unknowable--in which case this discussion is moot.

As for Asim's anecdote about the salesman, it was just an anecdote, he wasn't trying to prove anything, and therefore it doesn't contain faulty logic. Not to mention the fact that he didn't fault your logic, he just pointed out that for him most of your evidence and citations were invalid because they were unscientific. Logic is only as good as the premises it stands on, and so for him it was unconvincing. I don't see why you took his post so personally, because he never declared that you were wrong, nor did he attack you, he was just pointing out that your arguments failed to convince him and that his bias towards the need for scientific evidence was probably a good part of the reason he was unconvinced.
 

John Royster

Screenwriter
Joined
Oct 14, 2001
Messages
1,088
Jun-Dai,

I had hoped to no longer post in this thread as I (selfishly) have nothing to gain from doing so.

I can test and mess up any cable as I too am an EE and have access to o-scopes and OTDRs that can sweep a cable. If I ever have more time I may and puposely muck up a cable.

Till then I just bought a few CDs and am anxious to hear they sound until the wife gets home.

My little in-house test is probably anecdotal at best but when I hooked up the sony player as sole a transport the differences were way too noticible. That's when I figured I'd try the test just to see what was going on.
 

Jun-Dai Bates

Stunt Coordinator
Joined
Aug 16, 1999
Messages
148
John,

I hope that you will do that, because it would be interesting to see the results.

I don't think there is much point in arguing the validity of your test. We both know that it is too poor as scientific evidence to be even worth mentioning in a scientific paper, but I think we both also know that anyone reading this thread would probably be quite convinced of the difference between transports if we took the test under the circumstances that you did.

Proving something for oneself, proving something for people around you, and proving something to the world (or to a scientific community, at least) are three different categories of proof, and they each require their own type of evidence (sometimes they coincide).

Anyhow, if you are right and there is an audible difference between transports (I am ready to believe this, though I am not ready to believe it beyond doubt), I suspect that the 1s and 0s coming out of each machine are different. Perhaps they are using different formats for the data, and thus being interepreted in a different manner by the DAC (or by different DACs).


I am not prepared to believe (it would take a fair amount of evidence) that the timing of the 1s and 0s make up the difference. Even if I convinced myself beyond doubt that there was an audible difference and I analyzed the data from both machines and assured myself that they were the same, I would still seek explanations beyond sub-nanosecond jitter.
 

John Royster

Screenwriter
Joined
Oct 14, 2001
Messages
1,088
Speaking of listening to music and whatnot, wife just gave me my Valentine present.

Tom Petty box set.
Got me a good women guys, and boy does the set sound great. Excellent recording so far, highly recommended.
 

ManW_TheUncool

Lead Actor
Senior HTF Member
Joined
Aug 18, 2001
Messages
6,714
Location
The BK
Real Name
ManW
Good points, Jun-Dai. Discussions like these could often use such clarifications about scientific proofs, etc. Anyway, I feel more or less as you do although I'm really not in the position to throw $$$ at the kind of upgrades to make good use of this discussion.

John, I just almost picked up a Philips 963sa player for my own Valentine present--my wife is not that good to me.
Ran out to J&R, but they only have a display model left, and I didn't want to risk problems w/out possible quick replacement given what I've been hearing about the player. Would've been an all-around DVD and CD/SACD upgrade for me. I'm definitely prepared to believe it'll smoke my current player/DAC combo on the music side (as Jun-Dai would say). :wink:

_Man_
 

Forum Sponsors

Staff online

Forum statistics

Threads
344,464
Messages
4,710,803
Members
141,274
Latest member
Bats8711