Perhaps they are just playing how the music is mastered? eg base heavy or tremble heavy etc... To me they sound like a more refined upgraded sound signature of my HD25, and a huge upgrade in comfort. In fact most comfortable headphone period better in comfort than my HD800. These and my K550 covers all the genres of music I listen to which is pretty much everything with exception of country.
IMO, HD800 plays the music how it's mastered, and it doesn't sound like SRH1540.
1540 just has a rather unique sound sig IMHO.