"Audio Empire" wrote in message
...
I think you misunderstand me. In recording, you have two opposing goals:
(1)
to record peaks at as high a level possible without over-modulating
(allowable in analog recording, with occasional, momentary, excursions to
+3dB being of no consequence but anathema in digital recordings where
trying
to use bits that don't exist results in nasty noise.) and (2) while
simultaneously trying to keep the low-level info in the recording out of
the
mud and to do so without gain riding or using analog audio compression to
restrict the dynamic range.
Right, but no way is that difficult to do with the usual run of professional
gear running at 16/44.
Quantization noise is a straw man with modern digital equipment because
its
hard to do Sigma-Delta converters without introducing dither or something
like it.
Quantization noise might not be a problem with dithering, but rising
distortion certainly is a problem.
No it isn't. You may have been misled by plots showing THD+N. The rise is
due to the same noise floor appearing to contribute more as the signal level
went down.
The relevant spec is "dynamic range" which is measured with a -60 dB sine
wave. Generally the result of the measurement is dominated by noise, and if
you get at the actual spurious products due to nonlinear distortion, they
are equal or lower what you see with a -10 dB sine wave.
Please compa
http://home.comcast.net/~arnyk/pcavt...p-24192-60.gif
to:
http://home.comcast.net/~arnyk/pcavt...p-24192-12.gif
One is made with a -60 dB 1 KHz sine wave and the other is made with a -12
dB sine wave.
In both cases we see very similar spurious responses for the clearly
identifiable second and third harmonics (the only clearly identifiable
harmonics present) at about -128 dB down. The spurious response around 40
KHz is due to a switchmode power supply that was near by in a display.
These harmonics are so low as to be well below audibility by any known
generally-agreed upon criteria, and there is no rise in their amplitude even
though the signal level has been drastically reduced.