| It's very easy to hear the reason if you compare the results of a 24bit file captured back through an analog chain that's amplitudes in around an area of -90dBFs to -80dBFs - first truncating to 16bit and then second adding dither prior to requantizing.
More often than not, regardless of the noise floor of the chain - in these very low level areas the truncated version will fitz and distort as it heads into the noise floor - where as the dithered version will sound smoother as things head into the noise floor (albeit with some additional noise added to the least significant bit).
In other words ime the idea that things can be "self dithering" tends to be a myth - especially when you realize that more often than not a fade will be created digitally in the DAW - in which case even if there was a random enough bit of noise at the least significant bit to allow for some "self dithering" - this would get broken at the one place that dithering is most often needed.
Best regards,
Steve Berson |