You can use equalizer presets to change iPod's sound to suit a particular music genre or style.
For example, to make rock music sound better, set the equalizer to Rock.
Select Settings in the main menu. Then select EQ and select a music type.
If you assign an equalizer preset to a song using iTunes, then turn on the iPod's equalizer by selecting any equalizer setting other than off. The song will play using the iTunes setting if the iTunes setting exists on iPod.
You can't create custom equalizer settings on iPod, or transfer custom settings to iPod.