How to adjust iTunes volume on Mac OS X by smaller steps (iTunes loudness)

On Mac OS X systems you can adjust the volume in quarter-steps. To do so, press:

  • Option-Shift-F11 to reduce the volume by a quarter-step, and
  • Option-Shift-F12 to increase it by a quarter-step

I find that this is important when I use USB headphones, which tend to be too loud by default.

FWIW, you can also adjust the Mac OS X brightness the same way. Press Option-Shift-F1 to decrease the brightness by a quarter-step, or or Option-Shift-F2 to increase it the same amount.

I found this tip on macworld.com.