Is louder better?

Still, the louder you go the more distortion you get, so..

Yes - until the wife comes downstairs and gives you the stink eye as she walks by.

There are not but you hear the high treble and the low bass frequencies better at certain volumes because that is how the ear works.

I still forget with my planar/ribbons, that they ARE in fact playing loudly, they just sound not as thinkly loud as the driver-based speakers I have owned. Took me a while, but now I recognize that tradional cone driver "thickness", as distortion.

The downside is if I set the volume too loud, like rock concert levels, with difficult 20th century orchestral recordings, they can break up with things like ffff timpani shots.

Those times when I want head-banger levels, I use my Tannoys or Cerwin Vegas. Otherwise I listen to undistorted sound at high but realistic levels on my planar ribbons.

For me and my system, 80 dB, give or take, is just about perfect.