behavior of custom EQ?

I wouldn’t agree on that - the sound of “normal” EQ does not sound the best nor natural no matter, what some of reviewers are writting. I am an audiophile and I’ve heard a lot of music systems and not one of them which sounds natural does not sound as Clip on “neutral” EQ. Clip is after all just a piece of plastic to make you company on the subway and not a serious gear to listen music. So if you feel EQ makes your music more listenable just use it no matter what. I’m using it on my Clip.