The rate is 192kHz, not 196 -- just to make a small pedantic point.
Some
musical instruments do generate ultrasonic harmonics and/or noise -- but that doesn't mean
or imply that such components are relevant to our perception or appreciation of their
sound characteristics, and I know of no scientific tests to establish this issue one way
or the other. The ultrasonic componetns certainly contribute no pitch information -- tests
have definitely proved that point. So I think this element of your argument is irrelevant
and potentially misleading.
Not all outboard equipment is restricted to a
20kHz top end -- some is deliberately designed to extend to 100kHz or so -- but even those
that have a nominal 20kHz bandwidth will certainly have a far more gentle roll off at the
high end than a 44.1 or 48kHz digital system. That seems to me another good argument in
favour of 96kHz systems.
However, the issue is really one of theory versus
practicality, with the laws of diminishing returns thrown in.
Theory suggests
48kHz should be adequate, 60kHz would be ideal. Despite lots of misguided arguments, the
theory has never been invalidated, ever.
96kHz is probably the best current
compromise, sounding better than poorly engineered 48kHz systems, but not because the
higher sampling rate is actually required -- it's because the practical design constraints
of working at 96 have a negligable impact on the perceived sound quality.
There are also technical benefits which could be achieved in better engineered 48kHz
systems, but they more or less happen for free in 96kHz systems.
192 and 384
build on the benefits of 96kHz, in terms of even more relaxed filtering constraints, less
draconian noise-shaping and even shorter filter impulse responses... but place ludicrous
(and probably unworkable) tolerances on clock accuracy, as well as silly demands on data
storage and DSP overheads.
The bottom line, though, is if you like chasing
numbers, have the budgets, and believe it sounds better, go with 192 or 384. No one's
going to stop you. if you really want to, you can even release your material on DVD-A in
native 24bit/192kHz PCm. Or transcode to DSD and release as an SACD. Hell, why not go the
whole hog and sample at 2.8224MHz in native DSD
For those whose feet still reach the ground, 96kHz is probably the most cost-effective
format, even for budget applications. But there still isn't much wrong with 44.1 and 48kHz
systems for most people, most of the time, especially if you choose the equipment
carefully!
After six pages of this I'm getting bored now... shall we move on
to something more interesting... pretty please
Hugh