[ProAudio] The High-Resolution Challenge

[Scott Dorsey]

Jim Brown says:
> Perhaps 20 years ago, Ray Rayburn told me about hearing a demonstration 
> by Rupert Neve that he said clearly demonstrated the audibility of 
> ultrasonic components.

I wish this would stop going around, but Mr. Neve has said this many times
in many different places and he of all people should know better.

He talks about how a console had a channel that sounded different than all
the others, and so he did a sweep test on it and didn't see any frequency
response differences until he got to 65kc or so.  When he looked at the board,
he found a termination resistor missing from a transformer-coupled circuit.

He has repeatedly talked about this as if the 65kc aberration was what was
being heard, when in fact transformers behave rather differently in the
audible range when the termination is altered.  Had be used a distortion
analyzer he likely would have seen artifacts below 20kc.

He has in fact done some demonstrations in which he has added ultrasonic
components to a complex waveform played back through a nonlinear playback
system and... yeah.... everybody can hear the difference.  Because what
is occurring in the audible range is different.

>From my perspective, the fact that it IS audible is why we need to bandlimit
it out.
--scott