Around 70/75db seems to be a sweet spot. Appropriatley loud for most music. The lower it is the less resolution. Turning down the volume knob is like stepping down on the brake pedal. Less of everything. Low level listening is ok for background low resolution music.
At parties there are moments, later in the evening after a few shots, that a few songs get played 'hard' at loud volume. I admit I love the tightness of the bass and over all sound is impressive but only for a minute or two for demonstration. It is fun!