I didn't post it on the 1.2 forum because it is closed
But I didn't know that there is an updated manual for 1.3. Looks much better indeed, the misleading statement is gone. However, there are a few point which could be clarified even further (from the Digital Audio Page):
Therefore a sample rate of 40,000 Hz is the absolute minimum necessary to reproduce sounds within the range of human hearing, though higher rates (called over sampling) may increase quality even further by avoiding any aliasing artifacts around the Nyquist frequency. The sample rate used by audio CDs is 44100 Hz
This could give the wrong impression that higher sample rates than 40kHz (or 44.1?) are generally called "over sampling", though the term only applies if the sampling rate is multiplied by a natural number n
, thereby interpolating between the original samples. Yep, this may avoid aliasing when using inferior D/A converters (almost any recent converter does 4x-128x oversampling internally), or when doing nonlinear processing which could generate HF content above the Nyquist frequency. But of course, when you have PCM material which has a native sampling frequency of 96kHz or more, it isn't oversampled!
States (my bolding):
The 16-bit compact disc has a theoretical dynamic range of about 96 dB (or about 98 dB for sinusoidal signals, per the formula). Digital audio with 20-bit digitization is theoretically capable of 120 dB dynamic range; similarly, 24-bit digital audio calculates to 144 dB dynamic range. All digital audio recording and playback chains include input and output converters and associated analog circuitry, significantly limiting practical dynamic range. Observed 16-bit digital audio dynamic range is about 90 dB.
Well, the dynamic range 16bit PCM can possibly hold is about 96dB, that's it. If "oberserved dynamic" range is below that value, it is because there are not many analogue components which can record or reproduce such an dynamic range. Another point is that the recorded material hardly ever has a dynamic range above 50dB, even for very dynamic orchestral music. If one would look at recent rock CDs the "observed" dynamic range would probably be around 10dB (loudness wars rulez)!
But this figure hasn't anything to do with the technical limitations of the 16bit format! It's quite the same situation for 24 or even 32 bit audio. That's why this list is still mysterious:
Common sample formats, and their respective dynamic range include:
8-bit integer: 45 dB
16-bit integer: 90 dB
24-bit integer: 135 dB
32-bit floating point: near-infinite dB
The quoted value seem to be made up of thin air. I have no idea where they come from. As this page is a technical explanation I really think one should stick to the technical specifications and name the actual dynamic range a bit depth can hold. And that's 1.76+6.02n
, commonly rounded to 6n