It is completely dependent on the system, room, and your tastes. I have noticed that the better my system has gotten the lower the volume sounds best to me. Typically I listen at ~ 75db. Most of the experience audiophiles with good systems have seemed to converge on this volume. My system is shown.
What is the proper loudness for listening?
Paul McGowan via YouTube claims that each room, system and recording has a specific sound level at which music sounds most "real"
I've noticed this myself listening to my 3 different systems set up in differing rooms. Thought I was crazy to think so but I guess maybe I'm not?
Also, have notice in smaller listening rooms that lower maximum volume levels sound more real. Going too high on volume in a small room just overloads it and results in distortion
Any comments?