Flat, or "Off", for me.
What I would
really like to do is transfer the custom EQ curves I've made in iTunes, mainly the ones that I've specifically set for different earphones.
What I did was make a short track in Audacity that had a second's worth of sine wave for each of the frequencies labeled on iTunes's EQ sliders. I played it iTunes in Repeat mode, over and over, cutting a frequency's slider when I felt its note was too bright.
I did it with the iBook's own speakers, the Apple earbuds, some Sony earphones, and the home theater setup (streaming music via AirPort Express). After a few minutes of "boooo-ooeee-aaaah-eeee-EEEE-ssss",
each set of speakers/headphones ended up with a unique EQ curve where they sounded the best. Stereo imaging and tonal balance improved whenever I chose my new EQ curve appropriate for the speakers I was using.
But, I can only use them while listening on the computer, and never on an iPod. I've tried everything I could think of, such as assigning an EQ curve to each song (also easy to do for the whole library), but custom EQ settings don't get ported over.
So, I listen to the iPod with the EQ turned off. It interferes the least with the original recording's balance. If I were to use an included EQ while listening through Apple's earbuds, it would be "treble reducer", which cuts the earbuds' 4KHz and 8KHz peaks that I massaged out with my own setting on the computer.
BTW -- always better to cut than boost; helps minimize distortion.
