Yes, seriously, proper output leveling of DSD vs PCM playback is a minefield. Please read and absorb
this explanation, nicely laid out by Archimago.
Start from this sentence:
read what's after that , paying special attention to
Notice the assumption about encoding per specs. Also do read the nice summary on the
Roon site (including the warning about unfiltered DSD playback!)
And this DSD vs PCM level issue is actually separate from, and
in addition to, the possibility of incorrect LFE output from an SACD. The
LFE problem arises because the technology is
supposed to boost PCM LFE output by +10dB, because the LFE is
supposed to be 'printed' on the disc with a -10dB offset ("10dB low").
But it is
supposed to leave DSD LFE output alone, because DSD LFE is
supposed to be printed with no offset (Scarlet Book Spec).
If all those 'supposed to's are in place, it means that if there's a DSD-->PCM conversion step, the technology is still, in the end,
supposed to to
not boost the original LFE by 10dB.
But if any of the 'supposed to's are missing, either due to the technology or to the mastering, all bets are off.