Well well, after hundreds of dollars spent on multiple pairs of headphones and IEMs, I must say now that it’s not the case at all. I know what “natural sound” is to my ears and… it’s not flat. It’s not the harman curve, and it’s not “harman neutral”. And I know more.
What does “harman neutral” i.e.: “flat” sounds, to me? Dead. Because there’s not much bass (100hz-ish), the mids are laid-back and it’s treble-oriented. It’s a really airy sound that definitely does not remind me of all the shows I went to. Drum kicks sounds like they’re 2 meters away, voices are hidden under a veil of the microphone’s signature treble and hisses and I hear the highest frequencies of the cymbals (10-to-15khz+) like they’re in my face.
It sounds horrible but isn’t (well except for the 10khz+ TV snow hiss…). My ears aren’t as horrible as that. 