Double-click the Mixcraft icon on the desktop to start the program. Click the piano keyboard icon on one of the empty instrument tracks. Click "Show Details."
Click "Select Synth," then click the first synthesizer you want to use for the custom sound. Select a patch in the "Preset" column, then tweak the synthesizer's parameters, if desired, by clicking "Edit." You can, for example, change the frequency at which the synthesizer's filter activates by adjusting the "Cutoff" control.
Click the "Volume" box and type in a volume level for the sound, if desired. Click "Pan" and set the sound's position in the stereo field. A pan value of "0" means the sound is centered.
Click "Range" and select the notes you want the synthesizer to be able to play. If you're planning to play in a specific key signature, select only the notes that fall within that key signature. If you want the synthesizer to be able to play any note, leave this setting as is.
Set the "Transpose" and "Velocity" values, if desired. Transposing notes can be useful if, for example, you want to play lower-octave bass notes using the middle octave of the keyboard. The "Velocity" setting determines which range of MIDI velocities activates the sound. Leave the velocity set to "0-127" if you want every velocity to trigger the sound.
Repeat the process for any additional synthesizers you want to add to the custom sound. Click "Effect" and choose an effect to apply to the sound, if desired. Click "Edit" to adjust the effect's custom parameters.
Click "Set Icon" and choose an easily-recognizable image for the custom sound. Click "Save Preset," type in a name for the custom sound and click "Save" to save it.