Quote Originally Posted by skeptic
To know that non linear distortion levels of 0.1%, 0.01%, and 0.001 are not audible to human beings or that increases in distortion of these orders of magnitude are also inaudible doesn't take a research project into the history of auditory measurements.
I do believe that the higher orders of distortion, the 5th, and definitely the 7th and up, would be audible at 0.1%. However, that is still a moot point, and not what I was getting at.

Those numbers DO NOT have a ready correlation with the measured results from an audio device, for the very reason I just mentioned: we are more sensitive to the higher order distortion products. In many cases, we can not hear 1% 2nd harmonic, or a 2nd order type distortion, and THAT's why some tube amps sound better than they measure, they tend to have low order distortion, while SS amps with lot's of feedback tend to have lots of higher order distortions.

There is no simple metric, such as "less than 0.1% is inaudible", the papers aren't there, the correlation is not there. You can continue to ignore these aspects of audio, but sticking you head in the sand does not make the truth go away.

Jon Risch