Head-Fi.org › Forums › Equipment Forums › Sound Science › Jitter Correlation to Audibility
New Posts  All Forums:Forum Nav:

Jitter Correlation to Audibility - Page 16

post #226 of 290
Quote:
Originally Posted by robertsong View Post
 

As far as your source I have no intention of reading anything on jitter dated all the way back to year 2000.

Have the laws of mathematics or physics changed since 2000? Or is it because humans have evolved superior jitter detection since 2000?

post #227 of 290

I really do not understand all about jitter when analog devices introduce far more distortions (and usually easily audible unlike jitter).

post #228 of 290
Quote:
Originally Posted by wnmnkh View Post
 

I really do not understand all about jitter when analog devices introduce far more distortions (and usually easily audible unlike jitter).

 

Jitter causes audible analog distortions.   The distortions of high precision analog components can be extremely small. It's all relative.

post #229 of 290

What are you basing your statement that jitter causes audible distortions on? There's no indication at all that jitter in the amount found in even the cheapest home audio products is even close to being audible.

 

Perhaps you are thinking of 24/96 recordings that have high levels of super audible high frequencies. Those can create analogue distortion in the audible range in some cases.


Edited by bigshot - 2/4/14 at 10:58am
post #230 of 290
Quote:
Originally Posted by bigshot View Post
 

There's no indication at all that jitter in the amount found in even the cheapest home audio products is even close to being audible.

 

Goes back to my earlier statement -- If we cannot hear it/see it/feel it does it mean it doesn't exist?

post #231 of 290

If we can't hear it, it doesn't matter at all.

post #232 of 290
Quote:
Originally Posted by bigshot View Post
 

If we can't hear it, it doesn't matter at all.

Some can't hear a difference, some can. How can we say it doesn't matter at all?

post #233 of 290
Quote:
Originally Posted by Digitalchkn View Post
 

Some can't hear a difference, some can. How can we say it doesn't matter at all?


Because as far as we can rationally tell, no one can hear it at the common levels.  There are those who claim to hear it, but only are able to do so when they know what they are listening to and attribute differences to one component over another.  That ability 'mysteriously' disappears when they are blind to what is reproducing what they hear. 

 

Hence, no one can really hear it so it doesn't matter.

post #234 of 290
Quote:
Originally Posted by esldude View Post
 


Because as far as we can rationally tell, no one can hear it at the common levels.  There are those who claim to hear it, but only are able to do so when they know what they are listening to and attribute differences to one component over another.  That ability 'mysteriously' disappears when they are blind to what is reproducing what they hear.

 

Hence, no one can really hear it so it doesn't matter.

 

Mighy powerful statements - precise manifestation of ignorance.  These effects are real (analytically and physically), and only reason majority may not perceive it is because somebody understood the problem and has addressed it (or most of it) already.

 

Blind statements such as "jitter doesn't matter" is pure unadulterated ignorance by those who should search for conversations elsewhere.

post #235 of 290

even indirectly inviting people to leave a thread because you disagree with them is not convincing of your position's value - and likely in violation of head-fi's policy

 

the "some can" need to do so in controlled DBT listening tests in front of skilled investigators if the claim is to have weight in the Scientific community

post #236 of 290
Quote:
Originally Posted by jcx View Post
 

the "some can" need to do so in controlled DBT listening tests in front of skilled investigators if the claim is to have weight in the Scientific community

 

Conversely, those claims that it doesn't matter should be subjected to the same listening tests before their proponents make announcements that it doesn't matter.

post #237 of 290
Quote:
Originally Posted by Digitalchkn View Post
 

 

Conversely, those claims that it doesn't matter should be subjected to the same listening tests before their proponents make announcements that it doesn't matter.

 

There have been several DBTs of Jitter in studies, the key papers have been cited elsewhere they are the 1974 BBC paper (Manson)  http://downloads.bbc.co.uk/rd/pubs/reports/1974-11.pdf, the 1998 Dolby Labs paper available via the AES (Benjamin and Gannon) and the 2005 NHK (Japanese broadcaster) paper Ashihara et al. https://www.jstage.jst.go.jp/article/ast/26/1/26_1_50/_pdf  None of these placed the audible threshold for any kind of jitter below 10ns in any circumstances and no less than 20ns for music. There are a few pathological digital audio devices that can produce more than 10ns jitter but their performance is generally so poor that the jitter is the last thing you will worry about with them, the legendary MacIntosh MS750 music server being one discussed in the thread...http://www.stereophile.com/content/mcintosh-ms750-music-server-measurements

 

Here is a graph from the B and G paper showing the effect of jitter

 

 

the distortion product of adding a massive 300ns sine wave jitter is about 55 - 60db down on the fundamental, the 100ns jitter addition has a product a further 7db down, 10ns jitter would be even further down than that..B and G don't even bother with sub ns jitter, maybe somewhere there is someone with such superhuman hearing that it might be audible but if such a person existed they would be so many standard deviations from the mean that no rational hifi manufacturer would design products for them


Edited by nick_charles - 2/4/14 at 4:58pm
post #238 of 290
:smile:

Edited by anetode - 2/4/14 at 5:11pm
post #239 of 290
Quote:
Originally Posted by Digitalchkn View Post
 

Some can't hear a difference, some can. How can we say it doesn't matter at all?

 

You keep bouncing back and forth from inaudible to audible. What makes you think that jitter at the level it occurs in home stereo equipment is audible to anyone?

 

Here is the chart that Ethan Winer posted a few posts ago...

 

 

Note that with really, really bad jitter of 1 ns, it is down below the noise floor of redbook for all but the very highest frequencies. Even with 10 ns, which is pretty much unheard of, the jitter noise is down 80dB below the signal. Good luck hearing any of that. No human being can.

post #240 of 290
Quote:
Originally Posted by Digitalchkn View Post
 

 

Jitter causes audible analog distortions.   The distortions of high precision analog components can be extremely small. It's all relative.

 

The finest turntable in the world perfectly setup with a superb cartridge cannot get within a country mile of the low levels of time related distortion of even a bog standard $350 Marantz Cd player, for instance here is the effect of speed issues with a souped up Linn Sondek turntable

 

Look at the skirts !

 

here is the same 1K played back via a Cd5004

311Marfig3.jpg


Edited by nick_charles - 2/4/14 at 5:30pm
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Sound Science
Head-Fi.org › Forums › Equipment Forums › Sound Science › Jitter Correlation to Audibility