Is jitter audible and what does it sound like?
2015-08-26 17:29:30
I hope I put this in the right forum. You've probably been asked this a million times, but I trawled the web (mostly searching "dan lavry" + "jitter", as I figured he was the "master") as well as his forum, and I couldn't really find my answer, so I asked on his forum (which gave this response: http://www.lavryengineering.com/lavry_foru...f=1&t=7449) , and I'll also ask here to hear your opinion: If we're talking home audio listening (not recording), is jitter then audible, and how does it sound? I'm only talking about playing CDs and digital audio files from either a CD player, or your computer or a streamer through a dac into your amplifier. Let's also for the time being assume that the analogue to digital conversion during recording/mastering was done well to begin with, and let's assume that the converter you use is of fairly good quality. I discussed this with an audiophile friend. My own impression is that with 16 bit audio, jitter starts to become audible at -96 dB (without dithering), so with music recorded at sensible levels, it will not be audible, as all jitter is in the noise floor, and the music would mask the jitter. An exception could of course be orchestral music with a huge dynamic range recorded at a very low volume (so the noise floor would be raised). As for how jitter sounds, the video "Digital show & tell" on Xiph.org says quantization noise sounds like tape hiss from analogue tapes, but I might be mixing up quantization noise with jitter (is it the same?). On that website, there's also a file available for download with a 1 kHz tone at -105 dB. When playing that file there's background noise, which I assumed was jitter. In other words, jitter is present in all digital audio, but the amount is so low that you can never hear it except for in those extreme cases mentioned above. I asked Ethan Winer who said: "Jitter manifests as noise 100+ dB below the music, and is never audible. Nor does it create 'a lack of depth, solidity and a smearing of the stereo image.' You’re thinking of wow and flutter. :->)" In Ethan Winer's Youtube video "AES Damn lies workshop", he shows the following picture: My friend's attitude is that jitter is omnipresent and always audible and smears the stereo image etc. (like the comment above), so although he exclusively listens to digital audio he is starting to think vinyl might be the way to go to get rid of the issue of jitter. Surface noise, pops, clicks, etc. from vinyl can be filtered out by our brains, whereas jitter is an omnipresent 'grating' and unpleasant sound. I of course understand that when creating converters like Dan Lavry does, it's important to minimise jitter as much as possible in order to come closer to creating the perfect product, as well as creating an A/D converter that will have minimal jitter so the recording artists can raise and lower levels on different tracks as much as they like. But as mentioned, I'm only interested in audibility and listening at home – not in the technical aspect (measuring, etc.).