The moment my eardrums met the sound of my new nano, they were disappointed. Although i was using my trusty Koss PortaPros the bass felt weaker than my 1st gen iPod touch. the sound was also not as crisp as my itouch. after a few weeks i noticed an improvement in the sound. the highs and lows seem to be getting tighter, so is the bass. i wasnt aware that the equalizer is something that needs to be "broken in." but i suppose this is always the case. anyway, this device is worth it for on-the-go audiophiles but HiFiers with more discerning ears might need a good headphone amp.