I know lots of audiophile in China hate EQ, they just refused any kind of EQ because they think the pure sound without any EQ is the best sound, but they just forget that all record is made by EQ in the studio. Even the live music, the frequency response of the sound from the singer will change because the room. so forget the rule, just enjoy the music you love , not matter is is through EQ or not, anyway, you can set the EQ to flat if you love the original sound.
Also in my opinion, the whole audio system includes the music itself, source ( DVD or MP3 or any other) , amp, headphone and speakers, cables, but don't forge the room and your ear, because different room and ear have different frequency response , so sometime it does need a EQ so you can make the whole audio system become better.