HP-557R: Balancing Layered Tones
Use the following procedure to adjust the volume with two Sound/Tones selected:
1. If the [Guide] button is "On," press the [GUIDE] button to turn it "Off."
2. Touch the [Tone] icon on the screen.
3. Touch the [OPTION] icon on the screen.
4. Touch the [PART BALANCE] icon on the screen.
5. Touch the icons to adjust the volume of each part.
Refer to the Owner's Manual, pg. 40 for more information.