@almarg
As always I agree with pretty much all your comments.
I would add that the 24 bit will always look much better because at the same -90dbfs you have more bits to characterize the signal. The 16 bit looks square because there are only 2 bits to describe the signal. Even with a 20 bit DAC there are 6 bits available to characterize the sinewave at 24bit (so it looks smooth).
The zero crossing errors are the most alarming in those particular measurements.
"Audibly insignificant" depends so much on the frequencies. Low level noise distributed evenly and randomly across the spectrum is harmless. Rounding or Truncation can lead to high frequency noise of distinct tones which is harmful even at low levels which is why studios go to lengths to dither digital when reducing bit depth.
JA notes the jitter performance is less than desirable also. There has been much importance given to jitter even though it is very very low level noise - and this is because non-random jitter creates distinct tones that are not harmonically related to the music.
What is actually audible as distortion is very much related to tone and frequency rather than purely a signal level.
As always I agree with pretty much all your comments.
I would add that the 24 bit will always look much better because at the same -90dbfs you have more bits to characterize the signal. The 16 bit looks square because there are only 2 bits to describe the signal. Even with a 20 bit DAC there are 6 bits available to characterize the sinewave at 24bit (so it looks smooth).
The zero crossing errors are the most alarming in those particular measurements.
"Audibly insignificant" depends so much on the frequencies. Low level noise distributed evenly and randomly across the spectrum is harmless. Rounding or Truncation can lead to high frequency noise of distinct tones which is harmful even at low levels which is why studios go to lengths to dither digital when reducing bit depth.
JA notes the jitter performance is less than desirable also. There has been much importance given to jitter even though it is very very low level noise - and this is because non-random jitter creates distinct tones that are not harmonically related to the music.
What is actually audible as distortion is very much related to tone and frequency rather than purely a signal level.