Werner
pfm Member
So given that existing recordings were not filtered properly, a post processing stage of a 18kHz 3dB point, 4th order or more low pass should reduce these artifacts?
Ironically pre-oversampling era PCM1610/1630 recordings behave rather nicely in the upper treble, from an aliasing PoV.
Half-band recordings, on the other hand, should be replayed with an oversampling filter as I described. I don't think there is any DAC or CD player manufacturer doing this. They are all still set on printing "frequency response 20Hz-20kHz +/-0.1dB" in their blurb.
But we are deviating ...
Earlier question: why no cascaded noise shaping?
Well, each noise shaper is built on assumptions about audibility of the resulting noise/distortion. If you mix noise shapers, you start mixing assumptions, and the outcome may well be a mess.
If there is any chance that a noise shaping process is living downstream the signal path, then better apply TPDF at your own stage.