Apple Video System - Manual (Page 63)

Adjusting speaker balance and tone
To adjust the speaker balance, bass, or treble:
1 Choose Show Controls Window from the Windows menu.
2 Click the sound icon.
3 Drag the appropriate slider to adjust the sound.
You can also click anywhere in a slider’s track to move the
slider to that position. The sound adjustments take effect as
you make them, so you can monitor your changes.
Note: You’ll only be able to hear changes in balance if you
have a computer monitor with built-in speakers, if you’re
using external speakers attached to your computer, or if
you’re using headphones.
57 Learning About the Software