For all the hifi skeptics....

[altruistic.lemon]

As to 100khz tweeters - what else in the chain can go so high? CD players can't, neither can Record players, so it's a pointless exercise.

Commonly not, but it is possible. Frequencies of up to 122 kHz have been experimentally cut on records. CD4 records (quadraphonic) contained frequencies up to 50 kHz to encode what we would now call the surround channels.

Yup, but never recorded as such. They were to carry the info as you say for the extra 2 channels., so were within the normal 20-20 range. there's no point going over 20khz.

 

[MajorFubar]

Indeed, and additionally, I’m not even sure what kind of frequency response a typical studio master contains in the first place, so a distribution medium which can deliver ultrasonic frequencies could well be a wasted effort.

However, as I argued in the MP3 vs WAV thread (which kind of went off topic) I remain very open-minded to the potential benefits of hi-res digital audio, though if there are perceivable benefits, I doubt they have much to do with ultrasonic frequencies. I would offer - contrary to what seemed like an army of condemners, on that thread at least )) - that any benefits have more to do with a greater resolving-power. But I stress, I remain open minded and non-committal either way.