Quote:
Originally Posted by
leeperry 
page 28 of this PDF discusses the audibility threshold of audio jitter: http://www.scalatech.co.uk/papers/aes93.pdf
it seems that the ancient study all the myth debunkers like to cite as being God's word was conducted w/ mono signals from tape recordings, hah! the whole point of a lower jitter is to improve the stereo phase coherence and low level details clarity.
They talk about 120ps in 16bit stereo S/PDIF, that sounds more like it.
Lee, that AES paper predates Benjamin and Gannon by 5 years, you are referring to citations to the 1970s BBC studies, this is not the same thing I am afraid.
Quote:
Originally Posted by
EthanWiner 
What's not clear is if they are guessing about jitter audibility, or if they actually did a proper blind test on a large group of people. Concluding that jitter is audible just because it's above the noise floor of the medium ignores masking and other considerations.
--Ethan
It is a mathematical model, I have read everything Dunn and Hawksford have ever written on Jitter, they have never done empirical listening tests to determine audibility thresholds and Dunn's models are based on levels of 120db + room noise , so anywhere from 140db to 160db. So Dunn's extreme of 20ps at 20khz is a bit moot, what Dunn does contribute is a good enumeration of the precise level of "actual" signal degradation with jitter, viz even relatively small amounts do degrade performance below 16bits and 20bit audio is even more touchy about jitter. But the big question of whether this is in any way audible they do not address.
