humanafterall,
the 6G Nano has the same factory preset EQ settings as the iPod Touch,
accessible via the "Settings" menu.
I personally use a custom EQ technique that works for me,
but which many here claim has no effect.
in iTunes, on Playlist page,
View/View Options - select EQ
then select a factory preset for each and every song (e.g. Rock, or any other factory EQ setting name)
then in Window, select EQ - pop up window appears
adjust EQ slider bars as desired
(subtractive EQ is better - I want at least 3db down on everything)
select Make Preset
Name your custom EQ "Rock" (or any other EQ preset name, as long as it's the same name selected in Playlist EQ above)
- overwrite factory setting
(make sure the little 'EQ On' box in the upper left of the pop up window is checked)
select EQ-Rock on your iPod
Sync iPod
You should now have the custom EQ setting implemented on your iPod.
Works for me - don't know why some others here, can't get it to work for them.
Couldn't live without it.
On JH16/Nano combo - I use it to null out the Nano's 100Hz "hump" - really tightens up the bottom end.
Happy listening.