robert harley who has consummate ability to elucidate just about any description of a sound compares jitter to image stabilizing binoculars. its in the newest issue-#194 with the meridian speaker on the front, august.

...regards...tom

New issue of what? Not everyone lives where you live, and I'd like to read that.

"TAS" The Absolute Sound...

But image stabilization? That's a stretch.

One could call it the opposite. Image stabilisation addresses spatial but digital audio jitter is temporal distortion. The audio equivalent of image stabilisation would instead be fixing the spatial image between two stereo channels.

A better "analog world" example for jitter correction would be the stabilization of a spiral spring's circular motion with a pendulum in clocks.

including imaginary ones.

Audiophile gibberish belongs in general audio, not scientific discussion. Moved.

"including imaginary ones" WOW, i've found another genius here at h2audio forum!



sorry hlloyge, i wasnt thinking that everyone might not know that abbreviation. i usually post at audioasylum.com where most of us crazies know about it. tas has been doing a great job of evaluating audio equipment since '73 and coined the term 'high end audio'.

robert harley is a digital recording engineer who used to work for reference recordings i believe or a similarly fine company. he is also an analog lover of the first magnitude. when one review equipment at the level he does, MANY more details and nuances become quite obvious.

as for the stretch, perhaps so to illustrate the point, not make a direct equivalency statement. i for one could only imagine what exactly jitter is and how it might affect the sound. i think RH came pretty close with that verbiage.

It's easy to bandy about sarcasm with the word genius just as it is easy for someone to call a subjective audiophile delusional. So far I've not seen ample evidence to conclude either is right as of now.

However, arguing from an appeal to authority won't buy you much in these parts. It's more likely to elicit challenges to any and all people who claim to distinguish one thing from another to prove it through a double-blind test.

If you can't handle such challenges, this is probably not the forum for you.

I'd appreciate an in-depth description of what Harley actually wrote before the inevitable throwdown that is about to occur.

Hear! Hear!

You had me at "robert harley".

Is he? Well, I haven't heard of him anyways, but I know of jitter, so it would be nice if I could find that article to read it and possibly expand knowledge.

Harley was the one that concluded that the glass CD sounded more "analog-like" and other such things, so he's an expert in analog and an analog lover. He's got some articles at our favorite analog-lovers publication Stereophile.

Oh, and this piece of groundbreaking argument against DBT.

Yup yup yup

There comes a point when you're just communicating so badly you're going to get mocked for it, regardless of substance. This would be it.

this place is inviting as a toilet with a razor blade seat. i intend to invoke my will upon you, i just wont sit down. it seems this must be where audio annex is coming to rest. heheheh. cant fool me.

Show us some science, and we'll love you forever. Show us more of the same subjectivist nonsense and your welcome will be warm as a Canadian winter. That's just how it works. It's like walking into a Mac forum talking about how great Windows 7 is.

This is not exactly a great situation to try to be an apologist for the HA party line by explaining why our derison is so justified. Especially when some people really are being rude. (I love ya, krab, I really do, but was that really necessary?) But there are about 5 billion reasons why we should be contemptful of anything Harley says without engineering or psychoacoustic justification.

tommy, many of us (and I am specifically talking at least half of the posters on this thread) have a far more technical grasp of the mechanics of jitter than we are anticipating reading about in TAS. A good number of us have read Hawksford's papers on jitter simulation. A few of us know how to actually implement a jitter simulator. And most of us know how the audibility of jitter can be evaluated in a by-the-books psychoacoustic (or if you will, flat earth) fashion and grasp why such a large gap exists between what is considered audible in the engineering literature and what is considered audible in the high-end literature.

So, you make a post here - on a forum on scientific discussion - mentioning what we're all pretty sure is going to be a fluff piece that is going to be technically wrong... and you expect us to take it seriously? Of course we're going to chuckle (and mock).

You liken HA to a Audio Annex? I mean, really? HA is like the adult room compared to the kiddie rooms of, say, Audio Asylum. If you post, back your sh*t up, or be educated. Don't make personal insults and don't get emotional or personal. Don't make claims of audibility unless you can prove only aural senses are involved. These are not hard rules for educated adults to follow.


But hey.. you're an adult! And you want to learn! Pull up a chair! Let's get down to bidness. In terms of relating jitter to image stabilizing binoculars... image destabilization can be treated mathematically as an image convolution with a profoundly asymeetric kernel. Just to make this brutally clear:

x =

(CC-BY-NC-SA 2.0: attribution)

Convolution is a filtering operation, like a lowpass filter, or an eq, or an antialiasing filter. It doesn't really map very well to the domain of temporal distortions, at least not from the little bits of text you are quoting. The notion that it smears or occludes detail in a recording is only true in the most absolute general sense - that all distortions can do things like that - but if I were to try to formulate an accurate analogy between digital audio jitter and digital photography, I would think a better analogy would be taking a photograph with an image sensor whose pixel cells were radically misaligned with respect to one another:



But Harley didn't mention any of that in his article, did he? Of course not. I guess nitpicking on analogies is still nitpicking, but without seeing the article, it does not give me all that much confidence in it.

Um... comparing HA to a Mac forum is rather insulting. Of us.

Yeah, bad analogy, I know... I was trying to capture the flavour, but apparently unsuccessfully. Quitting caffeine is rough.

The most comprehensive, insightful, and freely available text about jitter and clock recovery is this (page 11) by Robert W. Adams. Pretty much said it all in 1994.

Edit:



Haha, what a funny coincidence! I just found that the above article even has a one page prolog explicitly showcasing this Robert Harley and how he was making a fool of himself by totally misunderstanding jitter and misleading others about it.

tas isnt scientific american nor does it claim to be anywhere near that pub. maybe RH didnt hit the nail on the head but tried an analogy for the non technical crowd. and perhaps this particular board at HA was a poor choice for an initial hobbyist post.

i can at least be respectful of the fact that none of you stooped to using emoticons. thank you axon for lightening the load on my neurons.

...regards...tom

A "good explanation of jitter in tas" eh? I've yet to see much other than obfustication in TAS. Well, I suppose seeing is believing, but if you don't mind I won't be holding my breath in the meantime.

You didn't read his Stereophile manifesto anti blind testing?

If you want some more giggles, pick up a used copy of his 'Complete Guide to High End Audio'; I perso nally was deeply, er, impressed by his views on the effect of copper crystal directionality on cable sound (and no, I'm not going to dig the book out an quote it again). But since I've been called rude for noting Harley's woo tendencies, here's a reviewer who gave it a '3' out of 5....trying to put the best face on it.

http://www.amazon.com/Complete-Guide-High-...By=addThreeStar



Btw, Axon...that bottom pic, c'est tres Seurat!

That should be a rhetorical question, otherwise one might consider me a liar. I should have known better based on the looks of the responses and the little that I did read since I gave mine.

It would seem that we need not have another anti-audiophool fest in this discussion since it appears that hifitommy has realized that he's amongst a group of people who understand digital audio to a depth that is beyond what is written in magazines designed to part people from their money.

Almost nobody here is able to read a copy of this article. If Robert Harley has indeed given a clear explanation of the sound of jitter then it should be straightforward for you to put in your own words the basis for his reasoning. If you attempt to do this you will almost certainly find that the foundations on which he bases his reasoning is not established knowledge but uncontrolled observations at best or unsupported wishful thinking at worst.

I just read it and it is a laughable comparison. The two phenomena have entirely different causes and anyone who has ever looked throught a decently mounted telescope should understand why. He might have gotten more mileage from a comparison with the modern image correction optics on the large ground based telescopes which is now common, but it is no more apt a comparison.

I don't think of openly misleading the reader, intentionally or unintentionally, as "good writing" myself.
That he can even make such a comparison suggests to me that he really has no idea of what digital jitter is.

Why would you assume that? Robert Harley earns his living as a writer/journalist/editor and his target audience is audiophiles like hifitommy. In this case the article would seem to be a good one assuming hifitommy's post is genuine which I would judge likely.

Nobody writing for an audiophile audience can deal with the audibility of jitter in a straightforward manner because it has become an important belief in the audiophile industry/community. To expect audiophile articles to be written for the audience here is daft but a significant number of posters seem to have this expectation.

I don't see why one, who had understood the concept, would be forced to use false analogies just to educate a dumb audience. They just need to be simple, not false.

If he knows better and just sells lies in the believe that's what his customers want, when they buy magazines to inform themselves, then so be it. But when his worshippers show up here and wave about his insight, whack'em! That's a natural side effect of believing in a quack. They have a choice.

I think he's saying if Harley understood it is irrelevant cause he needs to come to the conclusion that jitter is a problem cause it's a deeply held belief in the audiophile world. If he understands it or not is not gonna be a deterrent.

Clearly what Harley is doing is pandering to the belief among audiophiles that jitter is a problem. To do that he has presented a phony analogy to something they can relate to.

If it were a real analogy then the argument would fail, because jitter is not a real problem and the analogy would show that.

From a marketing standpoint it makes sense.
There's nothing much sexy about a grandfather clock. Image stabilization is useful, and I guess, a cool upper end teckie consumer thing to have. If your only interest is selling something, or selling people on something, why not link it to that?

The sale and marketing of real world phenomena for profit (e. g. Coca Cola) makes sense.

But he sale and marketing of the explanation of real world phenomena for profit is an assault against science.

Science itself is not perfect but quite successful at self-correcting its progress by adhering to a strict contract of scientific standard. Its results often too complex for the average public, so "explanation layers" between science and consumer make sense; and why should media supplying this service not make profit? That's fine. This tips as soon as you allow this "explanation layer" to cut loose from its scientific input and produce arbitrary output still under the scientific flag. This diverts consumer money away from companies actually bringing forward science to quacks and makes science look like some arbitrary, exchangable mind-set just like creationism.

I agree.
Seems to me he's selling Coke.

The purpose of marketing "information" is to provoke a feeling (a warm and positive non-rational response) toward a product or service. It has nothing whatsoever to do with rational thought and as such surely has no place on this forum. That goes for all marketing and PR.

Elections are analogous to the audio world. The more money that is spent on marketing and PR the more the focus is on (a) personal feelings toward the individual candidate (do you like him, is he a stand-up guy, would you have a beer with him) as against (b) the party's manifesto (i.e. the substantive rational expression of policy). You can't enjoy a beer with healthcare policy.

The same goes with audio. Very often what is called audiophile seems to me nothing more than the regurgitation of marketing / PR (a) whereas the focus at HA is (b) - rational and scientific information. The two are completely at odds with oneanother.

All marketing is merely emotional manipulation, and often it's hard to fight against precisely because it bypasses the rational. Which is why many of the recent audiophile threads on HA are like yelling at someone that part of the car's spec is not a gorgeous woman and no, she won't fall in love with you even if you do buy it. If someone has fallen in love with the fantasy (e.g. the audiophile and his cables), rationality is not going to cure them, because that's the very thing they've chosen to abandon to gain the warm fuzziness of their delusions.



Well it makes sense in the same way as "a criminal is someone with insufficient capital to form a corporation" makes sense. It "makes sense" when conscience is removed from the equation, and consciences don't get incorporated. But in fact, it has the opposite effect - it makes nonsense, in that it profoundly distorts market mechanisms, which rely on rational choices based on as close as possible to perfect information (i.e. hard spec style data) about products and services.

I think it would be helpful to make a stronger connection between the way businesses sell their products (marketing) and all this irrational BS that keeps popping up on HA - they are profoundly connected IMO.

C.

[EDIT: grammar]

Well if one equates jitter in digital audio to the shaking of a hand held binocular then one either profoundly misunderstands one of these two phenomina or is fibbing. Since the fact that optical magnification will also magnify the shaking of one's hand is so obvious and easy to understand, and wishing to be charitable on the truthfulness question, I was left with the likelyhood that it is digital jitter that he misunderstands, or so it seemed to me at the time.

That is a less charitable elaboration of exactly what I was thinking of in my earlier post.

Both rational choice and near perfect information are necessary properties of a classic economic model, not necessarily properties of the market itself. This classic model has raised serious doubt for at least two decades, because it doesn't work very well. The follwing was, for example, true before the credit crunch:

Both winners and losers had perfect information that they were dealing in hot air. The also knew they couldn't stop because it was such a cash cow. For many employes this was rational: you can't bring home a safe 6% p.a. when your peers are making that a month (at least) and all you would have to do was increasing exposure to very abstract risks as anybody else was doing anyway.

More contemporary theories as behavioral finance try to integrate that. But it is not said that a market with perfect™ information for everybody would be the best™ market.

I have recently witnessed, over on the Stereophile forum (an EPA Superfund candidate site if there ever was one), an admission from an aggrieved 'subjectivist' that insistence on 'science' stuff irks audiophiles because it tends to undermine beliefs in which they've invested a lot of emotional energy. I have always thought of this as the 'you're harshing our buzz' argument, and it was interesting to see it propounded by someone on the 'other' side.

It slightly reminds me of an ongoing ruckus in anthropology over the possession of some ancient human remains found out west that are of great scientific interest. Scientific metrics clearly establish them as not closely related genetically to today's Native Americans -- in fact they appear to be more Caucasian than NA - yet some tribes have traditionally revered the remains as 'their ancestors'. The government came down on the side of the tribes, not the scientists. It's a case where science was made to 'stand down' because its findings and goals are just too orthogonal to an emotionally, historically, and politically charged belief.

Apparently some audiophiles dream of receiving such special exception too, but they haven't 'earned' any such respect for their beliefs.

And if Harley's jitter article turns out to employ highly misleading analogy, it's of a piece with the MP3 article by Mr. Atkinson that was mastheaded with a pixellated version of the Sgt. Pepper's cover art -- as if to say to its audiophile baby boomer readership, 'see, what this looks like is what audio sounds like after you lossy compress it -- it destroys what we LOVE.'

I think you may be missing the point by considering the article from your point view and not that of Robert Harley or hifitommy.

Robert Harley is earning his living by writing articles like this. It is not a hobby but a job. The job is editor/journalist/writer for a magazine with the objective of making a profit by being an attractive vehicle for adverts for luxury goods. The topic is expensive home audiophile hardware but this is almost certain to be a lot less important than the job itself. To do the job well the article needs to be attractive to the target audiophile audience the advertisers want to reach and to be content that the advertisers are happy to have associated with their products. A straightforward article on the audibility is jitter is neither of these things. Companies advertising expensive audiophile CD players do want the content to state that jitter is inaudible in consumer grade CD players for very obvious reasons.

Hifitommy also does not want to read articles stating that jitter is inaudible in consumer CD players because jitter is one of the magical properties associated with the luxury goods that interest him. He wants to see articles that reinforce the importance and difficulties of jitter and generally add to the richness of his hobby.

Robert Harley has written an article that Hifitommy enjoyed reading. It is not an article I want to read and would probably consider it silly and factually wrong if I did like the previous one or two articles of his I have seen. I have no problem with this because I am not involved with either the magazine or consider myself part of the audiophile world. Nor do I think Robert Harley or hifitommy should see things from my viewpoint or the scientific viewpoint or some other viewpoint if they are not interested.


Now here we have agreement.

At risk of getting too OT (perhaps if you want to discuss this further we can via PM), but just to say, there's a profound difference between buying a stereo or a car (i.e. the world of consumer goods - where marketing is rife) and the world of speculation / market manipulation, interest rate arbritrage, dumping toxic debt into pension funds and CDOs etc. The former can function with good information and decent competition (and is relevant to the audio consumer and marketing), the latter is all about operating behind the scenes and off-balance sheet (and has no relation to the audio consumer or marketing). That said, good luck with your per millisecond algorithmic trading.

C.

I'm surprised that no one has posted the link yet. May I?

TAS article

Scroll down a little ways until you get to the TAS article.

Edit: Here's a more direct link: TAS article

Seems more like an abstract than an article; maybe the actual article is in the printed mag?

-bandpass

Moderation: Removed unnecessary quote of the previous post.

That's even worse than what I had expected.

Let me give you the executive summary and spare the reading:

1. Canon Image Stabilizer binoculars are awesome! Scientifically same amount of information within image, but much better visible without movement. Brain can focus on details without having to waste effort for its own image stabilization.
2. Esoteric G-0Rb, a $16,000 rubidium-based external clock, is awesome! Scientifically same amount of information within signal, but much better audible without jitter. Brain can focus on details without having to waste effort for its own jitter correction.

So the main point of the article is "awesomeness". The visual analogy is far-fetched and doesn't educate non tech people one bit. Besides that according to all known data, exchanging the clock in a consumer DAC with a rubidium based one should not be distinguishable! So a better (while still flawed) comparison would be already perfectly stabilized binoculars vs. even more stabilization. Technically maybe a difference, subjectively indistinguishable.

The just advertises that jitter elimination is awesome, because some unrelated, but cool sounding, image stabilization technology is also awesome.

The table of comments indicates the article is a maximum of 2 pages. If 1 page is an advertisement then this is probably the whole article. Also, the TOC says it's an editorial, not a proper article.

rpp3po points out that the article doesn't say anything much and the analogy is flawed. But this is only known by the expert. As I'm a layman myself, the article makes sense to me. If I had not been aware of all the nonsense in audioland I probably would have said "That's a easy to understand explanation of jitter." But I've learned to pretty much ignore anything I read in audio magazines.

Speaking of atomic clocks to synchronize digital audio signals, why does he need a $16K device? I've actually done this with a Casio Atomic Watch. The watch receives the atomic time via radio signal. You wouldn't believe the difference in sound versus not using the Casio atomic watch. The tick-tock of the music is more stable. The radioactive atomic fuzziness is less pronounced, and the music has a beautiful glow around it. Without the watch the sound is also very glassy, but I've found this to be minimized by removing my glasses. The atomic microdynamics of the sound are much better.

It's just a one page, 7 or 8 paragraph article. The four title lines are in very large font.

I've done digital photography with Canon cameras for about 5 years now, and I'll tell you, if audiophiles were "photographiles", they would HATE IS. Actually some birders rant against it, preferring a very sturdy tripod instead, and with some you can't even get into their thick skull that IS is about practicality more than about ultimate quality. A non-IS lens will tend to be sharper just because the IS lens requires a few more glass elements. IS, strictly speaking, can only introduce distortions to the image. At best, the distortions won't be greater than the film/sensor resolution, and at worst, you'd lose some sharpness and/or gain some aberrations.

IS is just a practical aid (I love it -- the pros greatly outweigh the cons), but it can also limit the design of the lens. Just like with zoom lenses (which are also a practicality/image quality trade-off due to extra elements) they can restrict what you can realistically do with it, like maximum aperture and possibly focus range. For instance, there are no Canon (or any other brand I know) zoom lenses for 35mm film with max aperture larger than f/2.8, and the only IS lens with aperture larger than f/2.8 is the über-expensive and one of the newest Canons, the 200mm f/2.0 IS *drool*.

It is a "solution" to a problem that doesn't really exist, IMO (much like fancy wires in audio). If you need detail you mount the optic, and if you need portability you use a low enough power so that the shaking isn't too obvious. Can you really see more detail from a 35mm objective image stabilized at 10 or 15 power than you could with the same objective size at 5 or 7 times not stabilized? I rather doubt it, and for most binocular observation high power doesn't help all that much anyway.

Amature astronomers (who do really want extreme detail) simply mount their optics sturdily and usually get rid of the extra lenses needed to "erect" an image since it doesn't matter all that much if you are looking at Mars, and each optical surface, as you point out above, necessarily degrades detail.

Now a real problem for astronomers is the shaking of images that comes from atmospheric turbulence, as this causes real loss of detail. Modern adaptive optics are really helpful there, especially for the professionals who are imaging and rarely use their own eyes directly. This technology really does work and has given new life to many ground based telescopes that would otherwise have been junked, but which can now do cutting edge research.

Before this gets too OT on the practicalities of carrying movie-grade tripods around; surely the key difference is that image motion caused by hand holding powerful lenses is manifest on non-critical observation, causing obvious defects in normal use of the images.

I would certainly agree.