Roon defaults for volume leveling for both mobile and stationary platforms is -14 LUFS, and -5db where loudness is unreported (i.e. streaming). Personally I have found these defaults with Classical do not work for me and usually set at -18 LUFS and as low as -21 LUFS (depends on system) and I usually set -2db or -3db for unreported loudness. For Pop music I usually just leave the roon defaults.
It used to be quite common to see users post about a lack of “life” from roon compared with other players which was often solved by playing around with LUFS settings. Those posts don’t seem to occur now. I think the LUFS defaults were changed at some point but I can no longer remember what they were originally so I may be mistaken.
I would be interested to know if roon plans to change the loudness defaults in the light of this research or if others have found themselves manually adjusting the loudness settings to suit their listening preferences.
I use -18 LUFS / -9 dB
I use -21 LUFS / -8 dB - Defaults are -14 / -5 still and as I recall have been since the introduction.
I remember the original default being -23 LUFS, which I thought was rather low.