[Vorbis] Sample rates higher than 48k? 24-bit depth?

[Monty]

Higher sampling rates are not trying to provide more high-frequency
headroom; they're designed to allow using less aggressive analog
lowpasses during sample and playback.  The filters required by 44.1kHz
and 48kHz sampling rates need to be extremely aggressive to avoid
aliasing as they have so little room in which to roll off.  This leads
to a very harsh filter that usually includes a plethora of ripple in
the passband, rolling off too early, aliasing, or all three.  A 96kHz
rate makes getting a good result out of the lowpass much easier (you
have a full octave for rolloff instead of a tiny sliver of spectrum).

Monty