One reason I find the HE-500 fatiguing - It sounds best loud.
I never listened to my he500 loudly...when off my head u for sure couldnt hear the music in another room... I am guessing its all about the amp who drives it..i never ever had the volume past 22:00 on my 337.. And i listened to classical music also with those very low hard to hear very softly played instruments..playing sensitive parts..i could hear all..didnt need to put the volume up...
But as i said many times..my hearing is probably very good if u all need blasting loud volumes to get a decent sound.
to be honest...i think its more about ur hearing ability (or disability) then the headphone/amp itself imho ofcourse..when i walk into a trainstation its almost like i walk into a disco when i see young ones not older then 15 years old having beats? playing so loud it must be brain damaging...i am guessing when older they for sure will have damaged hearing.. And so need multi of watts to get a decent sound from their rig. ..but hey..am no ear doctor.. but am guessing emotiva and the likes will come up with an even more powerful affordable amp when the youngsters will get our age