Start Acoustica Mixcraft. Click the "Change Instrument" icon, which looks like a piano keyboard, underneath "1 Instrument Track."
Scroll to and click "Vox" in the "Category" list. Click on one of the synthesized voices in the "Instrument Preset" column.
Click the "Show Details" button. Type in new values for the voice's "Vol," "Pan," "Range" and "Velocity" settings, if desired.
Click "Musical Typing." Click a key on the virtual piano keyboard that appears to preview the synthesized voice. Click "Close Window" to apply the new instrument to the track.