drewfx1
Had you mentioned in the first place that it was an example of dithering to a 10 bit level then I wouldn't have commented. But you neglected to say that and thus people may have mistakenly believe your example (and any conclusions based on it) were based on 16 bit resolution rather than 10 bit resolution.
Sorry, but to clarify. I have not "dithered to a 10 bit level". I have exported into 16bit with/without dithering, in Sonar, from a clip recorded into 24bit file by the interface with -113 db RMS SNR (RME).
But as I have explained in my original post as good as I could (in not my native language), 16bit format is fixed point and so it degrades precision at lower levels. At the same time, not dithering artifact/noise has absolute (-90dB) level, independent from the signal level. So on lower volumes, original signal is degraded (in example case down to 10bit or whatever precision, I have not really checked numbers) while dithering noise stay on the same level as it is for full 16bit. And so, after amplification, it becomes clearly audible.