There currently seems to be an issue with Roon’s phase inversion feature, whereby any clipped samples are ‘wrapped around’ and instead of just clipping at positive 0dBfs, will go to negative 0dBfs, creating significant distortion.
This can be audibly demonstrated very easily by playing a track with samples at 0dBfs, or that contains intersample overs.
If you listen to ‘Bon Voyage’ by Droeloe ( https://song.link/gb/i/1170076107 ) and then enable phase inversion as shown:
Then just listen from 0:20 to 0:35. You can hear obvious and very significant distortion. Which immediately disappears if you disable the inverted phase option.
This can also be shown by looking at the waveform. I recorded this with VB-Hifi cable which is a bit-perfect virtual cable.
Original (phase inverted in audition to more easily compare to Roon’s phase inverted output):
Roon Inverted Phase output:
You can see that at the point where the cursor is (as well as a few other points), samples suddenly wrap-around to negative 0dBfs when that doesn’t happen in the original file or Roon output with phase invert disabled.
It seems to only do this when the waveform hits a positive 0dBfs. If it clips to negative 0dBfs it does not wraparound to positive 0dBfs.
The phase invert feature should not be altering the content like this, both because this sort of distortion/error should never happen anyway, but also because it shouldn’t be altering samples at all other than literally flipping them positive to negative and vice versa.
