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What does jitter sound like?

Posted: Sat Feb 18, 2012 12:07 am
by DancingPriest
I've being doing some quite attentive listening recently. And now that I'm listening for it I think I'm hearing it a lot.

It sounds like a weird modulation in the quiet parts of a recording. But at moderate volume it seems to be a mist that the sound is traveling through

I love my analogue and all the work it takes, but I always subscribed to the bits are bits theory when it comes to electronic sound. So, on a digital signal line, if it gets there: it's perfect.

I do remember however, jkenny playing with attenuators on Fran's system and I did hear a difference, like a very very thin veil being lifted.

The veil I'm hearing is not F'ing thin at all, more like an big cloak wired to a switching power supply.

Help?!

Re: What does jitter sound like?

Posted: Wed Feb 22, 2012 4:39 am
by jkeny
This is a quotation from Bob Katz, well known recording & audio mastering engineer posted herehttp://www.digido.com/audio-faq/j/jitter-better-sound.html
After an engineer learns to identify the sound of signal-correlated jitter, then you can move on to recognizing the more subtle forms of jitter and finally, can be more prepared to subjectively judge whether one source sounds better than another.

Here are some audible symptoms of jitter that allow us to determine that one source sounds "better" than another with a reasonable degree of scientific backing:

It is well known that jitter degrades stereo image, separation, depth, ambience, dynamic range.

Therefore, when during a listening comparison, comparing source A versus source B (and both have already been proved to be identical bitwise):

The source which exhibits greater stereo ambience and depth is the "better" one.

The source which exhibits more apparent dynamic range is the "better" one.

The source which is less edgy on the high end (most obvious sonic signature of signal correlated jitter) is the "better" one.
And a reply:
The better one, and it is better, is also easier to listen to. . . less fatiguing. I would also add to this that the low end just "feels" bigger and more solid. This is perhaps a psychoacoustic affect more than a measurable one. It may be that the combination of a less edgy high end and greater depth and width makes the bass seem better.

All of this makes sense if thought of in terms of timing (that is what we're talking about isn't it ;-]). With minimal jitter nothing is smeared, a note and all its harmonics line up, the sound is more liquid (a term probably from the "audiophile" crowd but one which accurately describes the sound none the less), and images within the soundstage are clearly defined.

Re: What does jitter sound like?

Posted: Wed Feb 22, 2012 10:47 am
by Diapason
That's very interesting. That sounds a *lot* like my occasional bad sound symptoms. Hmmm...

Re: What does jitter sound like?

Posted: Wed Feb 22, 2012 10:54 am
by jkeny
Diapason wrote:That's very interesting. That sounds a *lot* like my occasional bad sound symptoms. Hmmm...
Here's the thing though - I believe other issues can give rise to some of the above symptoms too, for instance RF (radio frequency) noise can manifest as increased sibilance &/or a more diffuse sound stage. It really is all about the interaction of these various extraneous & unwanted influences & how well your system can handle them.

Re: What does jitter sound like?

Posted: Wed Feb 22, 2012 11:08 am
by Diapason
I must admit I've learned an awful lot recently about the different effects that "things" can have. Makes you think.

Re: What does jitter sound like?

Posted: Wed Feb 22, 2012 1:56 pm
by Fran
Just to echo what John mentioned above.

I would say that its easy enough to demonstrate the difference of lowering jitter. Tom/Derek have heard the effect when you insert an RF attenuator on the S/PDIF line to a dac. Immediately you get a jump in apparent resolution, and coupled with that the bass becomes tighter and highs become cleaner.

Its hard to describe on paper (screen!) but to actually hear it, it very discernable.

So the opposite is also true. More jitter=harsher and less distinct treble and looser bass. Things like unrealistic, splashy hit hats or brush work is a classic.


Fran

Re: What does jitter sound like?

Posted: Wed Feb 22, 2012 2:49 pm
by Diapason
Fran wrote: I would say that its easy enough to demonstrate the difference of lowering jitter. Tom/Derek have heard the effect when you insert an RF attenuator on the S/PDIF line to a dac. Immediately you get a jump in apparent resolution, and coupled with that the bass becomes tighter and highs become cleaner.
I believe I heard that myself at your place, and very compelling it was too!