Positive Feedback: Article on Jitter.

[MylesBAstor]

"Can any WBF member describe with detail a properly carried blind test in which he has participated, its statistical analysis and conclusions?"

I am sure that audiologists have a professional organization with a technical journal and peer reviewed papers. Those who study psychoacoustics using many methods like FMRI probably also perform scientifically rigorous tests to try to understand the science of sound and hearing. For audio equipment manufacturers maybe not. It's rather surprising that considering how Toole claimed to have scientifically determined what people like if not what is most accurate, Harman isn't producing speakers that dominate the marketplace. Did he draw the wrong conclusion or has Harman simply not capitalized on what it learned from him?

What's next IQ tests?

Oh yes and all these clowns running around in white lab coats with their pocket protectors, sliderules, computers, measuring equipment, etc. still fxxxed up the sound of Carnegie Hall. So much for all their mathematical models that showed the sound of the hall before and after were identical (remember the concrete slab that was left behind under the stage?). And no I didn't do a double blind test.

 

[microstrip]

(...) It's rather surprising that considering how Toole claimed to have scientifically determined what people like if not what is most accurate, Harman isn't producing speakers that dominate the marketplace. Did he draw the wrong conclusion or has Harman simply not capitalized on what it learned from him?

Although I am not an owner of any Harman products, except for my more than 8 year old AV amplifier, and I have very little experience with their speakers, I feel that your argument line is not fair. Trying to connect the research quality with market success, and creating this dual exclusive possibility is an oversimplification and too primary. F. Toole research was always exposed to the public and strongly influenced the designs of most speaker manufacturers. BTW, IMHO the most important of his research is not the few sensationalist quotes and challenges that show in the net mostly for marketing purposes, but the knowledge and methodology that he spreads along over 500 pages in his book "Sound Reproduction".

 

[Phelonious Ponk]

I've reached my own personal conclusion regarding jitter; it requires no further testing. I've decided Amir can hear it but I can't. More generally, I've decided that jitter in decent quality, contemporary digital audio is an issue so minor that if you haven't trained yourself to identify the artifacts of jitter and you're actually listening to the music instead of for the artifacts, it's highly unlikely you'll ever notice it.

I have no proof of that, but I can't hear it, so it's what's good enough for me.

Besides, I've asked "what does jitter sound like?" on several audiophile forums and I've gotten pretty consistent answers -- "harsh," "brittle," "bright," "fatigueing," "cold...." In other words, it pretty much sounds like everything else that's objectionable at the high end of the curve. And I've heard all this stuff, of course, many times. And I could go home and hear it right now if I wanted to. And then I could get rid of it, and return to clear, open and detailed without harshness, quite easily. And I could do it without changing digital sources, DACs or cables. So it wasn't jitter.

That's my story and I'm sticking to it.

Tim

 

[Phelonious Ponk]

Although I am not an owner of any Harman products, except for my more than 8 year old AV amplifier, and I have very little experience with their speakers, I feel that your argument line is not fair. Trying to connect the research quality with market success, and creating this dual exclusive possibility is an oversimplification and too primary. F. Toole research was always exposed to the public and strongly influenced the designs of most speaker manufacturers. BTW, IMHO the most important of his research is not the few sensationalist quotes and challenges that show in the net mostly for marketing purposes, but the knowledge and methodology that he spreads along over 500 pages in his book "Sound Reproduction".

I tend to think the watershed discovery of Harman, if not Dr. Toole, is the fact that listeners, trained and untrained, young and old, audiophile and otherwise, consistently prefer speakers with a more accurate response that is more even off (and further off) axis.

If you think about it for half a second, it seems obvious (a "duh!" moment). But many, many very expensive and celebrated speaker designs have failed to meet this simple criteria. Many continue to. Yet it simply makes sense -- if your speakers sound bad off-axis, that's what your first reflections are going to sound like; that's what a big part of your direct sound is going to be like if you're not right in the sweet spot. Applicaton of this simple principle is, I think, the solution to a bunch of old audio problems.

Tim

 

[microstrip]

(...) Besides, I've asked "what does jitter sound like?" on several audiophile forums and I've gotten pretty consistent answers -- "harsh," "brittle," "bright," "fatigueing," "cold...." In other words, it pretty much sounds like everything else that's objectionable at the high end of the curve. (...)

Tim,

IMHO you were given the wrong answer - there is no sounds like of jitter. Again IMHO, the acoustic signature of jitter is what creates the differences in sound of typical of CD transports - we all know they are bit exact. And although they sound very different, I have never owned a high-end CD transport that sounded "harsh," "brittle," "bright," "fatigueing," "cold...." . And I have owned a lot of them

May be people were most of them addressing the effects of very poor quality CD transport systems or induced jitter by electronic means and this particular type of jitter had this type of sound - but not all horses and jitters were born equal!

 

[egidius]

...and you're actually listening to the music instead of for the artifacts, it's highly unlikely you'll ever notice it.

I have no proof of that, but I can't hear it, so it's what's good enough for me.

Tim

Tim, thats a great notion; I catch myself often not hearing a thing, because I listen to music ;-)
Of course, there are always the moments when you try to discern, but the better my system gets, the less I need that..Egidius

 

[Soundminded]

I've reached my own personal conclusion regarding jitter; it requires no further testing. I've decided Amir can hear it but I can't. More generally, I've decided that jitter in decent quality, contemporary digital audio is an issue so minor that if you haven't trained yourself to identify the artifacts of jitter and you're actually listening to the music instead of for the artifacts, it's highly unlikely you'll ever notice it.

I have no proof of that, but I can't hear it, so it's what's good enough for me.

Besides, I've asked "what does jitter sound like?" on several audiophile forums and I've gotten pretty consistent answers -- "harsh," "brittle," "bright," "fatigueing," "cold...." In other words, it pretty much sounds like everything else that's objectionable at the high end of the curve. And I've heard all this stuff, of course, many times. And I could go home and hear it right now if I wanted to. And then I could get rid of it, and return to clear, open and detailed without harshness, quite easily. And I could do it without changing digital sources, DACs or cables. So it wasn't jitter.

That's my story and I'm sticking to it.

Tim

I think you've jumped to some conclusions. I don't know if I can hear it or not. Amir thinks he can hear it but he's yet to offer any evidence one way or the other. I have no idea how you can know if you can or can't hear it. This is why I said I hope Amir has devised a test that will isolate only jitter as the variable between two sounds to be compared. Many of the sounds described as jitter might be attributable to a FR peak in the system at around 4 khz, a very typical source IMO of the hardness characteristic of some cds and also of some vinyl phonograph records although they are much fewer. I think when someone comes up with a new theory like this (yes I know it's been around awhile) and wants to sell a cure it's up to them to prove that you really can hear it. From the graph, what was shown was so small that it suggests that it is not audible but only through very carefully controlled tests could that be determined.

 

[NorthStar]

http://www.tnt-audio.com/intervis/pearsone.html



Harry Pearson formerly of the absoute sound.

---- I don't fully agree with Harry on that one, but I do understand where he's comin' from.

__________________

If digital jitter was recorded in the music recordings, is there any machines out there that can remove it?
...DACs, Upsampling, USB de-jittering, Downloading/streaming/smoothing high rez audio, Master clocks, transports, laser reading, all that jazz.
Where are we now regarding the total elimination of jitter; in & out? ...From inside out.
...Going in and coming out.

That's when I switch to my albums. ...Occasionally. :b

 

[Gregadd]

I don't fully agree with Harry on that one, but I do understand where he's comin' from.

But don't you find the parallel with Ethan's comment ironic?

 

[NorthStar]

But don't you find the parallel with Ethan's comment ironic?

---- No, because Harry, Ethan, you, me, him, her, us, them, we all make this world running the way it turns; just like a CD or an LP or a RtR tape. :b

I mean, who's the real expert? The guy in a scientific jumpsuit, the audio writer/reviewer in a regular suit, the 'audiophile' of the cyber space without a suit (completely nude), or the explorer of all things music related? ...Dressed casually. :b

Or Mike Lavigne?

 

[Gregadd]

If I can editorialize a bit: Years ago - before the "blogger" generation where anyone could spout off like an expert - magazine writers actually knew what they were talking about. And when they said something erroneous, a knowledgeable technical editor would catch it. Today everyone is an expert, and some just make stuff up as they go. It seems too many people lack basic logic skills to separate fact from BS.

Ethan

quite dislike most of the Internet discussions on audio. They are the deaf trying to speak to the deaf. I find few stimulating ideas and almost no good criticism on the Net, where everyman becomes a "critic". And where virtually every man is unqualified to criticize.
I don't think there's any future for Internet magazines that are free. Once someone figures out how to publish on the Net profitably, then it will be a different ballgame. But some of us hate reading off a television screen and want to hold our magazines in our hands.

Harry Pearson

Really You don't see it?

 

[NorthStar]

---- Yeah yeah, but it's one-way-street here it seems to me.
Yesterday is gone, today is brand new; we can only go forward.

Personally, I always try to never (ever) stay in the same trouble waters, or have the wrong perception.
Each one of us we have our own interpretations, and the fundamentals are as exigent as our energy is derived from them.
...Way of speech simply to reaffirm the unabsolute in life.

 

[opus111]

Again IMHO, the acoustic signature of jitter is what creates the differences in sound of typical of CD transports - we all know they are bit exact. And although they sound very different, I have never owned a high-end CD transport that sounded "harsh," "brittle," "bright," "fatigueing," "cold...." . And I have owned a lot of them

In my more restricted experience - I'd not say I've owned a lot of players, perhaps a dozen or so, the SQ differences haven't been due to jitter. They've been down to common-mode conducted noise. The worst sounding transports (actually no dedicated ones, just players used as transports) have switched-mode supplies which tend to throw around quite a bit of CM noise. Change to a well isolated linear supply and the SQ differences disappear. Alternatively modify the DAC so its immune to this kind of noise.

So far in my development of multibit DACs jitter hasn't been an issue. If I were developing S-D DACs, perhaps it would be. By 'not an issue' I mean to say its not the low-hanging fruit of SQ in respect of DACs.

 

[opus111]

Besides, I've asked "what does jitter sound like?" on several audiophile forums and I've gotten pretty consistent answers -- "harsh," "brittle," "bright," "fatigueing," "cold...." In other words, it pretty much sounds like everything else that's objectionable at the high end of the curve. And I've heard all this stuff, of course, many times. And I could go home and hear it right now if I wanted to. And then I could get rid of it, and return to clear, open and detailed without harshness, quite easily. And I could do it without changing digital sources, DACs or cables. So it wasn't jitter.

I can't see any reason why jitter would sound like those things that typical audiophiles describe it as. To me, all those things are the sound of noise (sibilance) in the system not jitter. Perhaps Amir would chip in as to how jitter sounds to him? I speculate that if I could hear jitter it'd sound more like a soft-focus effect but I'm not yet sure I do hear it.

 

[Ethan Winer]

all these clowns running around in white lab coats with their pocket protectors, sliderules, computers, measuring equipment, etc. still fxxxed up the sound of Carnegie Hall.

Talk about anti-intellectualism. So some acoustician made a mistake, and that invalidates all of audio science? Last year a weather report predicted rain but it never came. By your logic meteorology is a sham too.

--Ethan

 

[NorthStar]

-- What is science? It is an exploration into newer discoveries. It always permutates, with time.

 

[Gregadd]

Of course the meteorologist having predicted rain will never ignore empirical evidence that it didn't. The designers of Carnegie however continue to use numbers to deny empirical evidence that the sound is not quite right.

 

[NorthStar]

-- Hey those six expert scientists on earthquake's predictions (seismologists?) in Italy; they were all convicted, and condemned to spend quite a long time in jail! ...Years if I recall, but I might be wrong too.

You guys know what I'm talkin' 'bout?

 

[Gregadd]

http://www.cnn.com/2012/10/23/world/europe/italy-quake-scientists-guilty/index.html

 

[NorthStar]

http://www.cnn.com/2012/10/23/world/europe/italy-quake-scientists-guilty/index.html

---- Yes, six years in jail; I know that story very well as I followed it (thx for the link).

Italy's ground jittering!!! ...And the court's jittering too, as the verdict also!
That news sent, and still send a lot of 'jittering' among all the Earth's expert scientists!

In Canada, our government is dismissing science in the name of food poisoning, and global warming is behind oil exploitation!
They just don't have their priorities straight in some places of our planet, and the people ruling it!

_______________________

Jitter is serious business, in audio as well, and you can feel it too!
...Your brain can register it, and its negative dysfunctionalities.