Set User-Definable Keyboard Split Point (PRO FORMANCE +)

1. Set the MIDI Channel Selector control to Split.
2. Play a key on the keyboard (the last note you play will be used).
3. Move the selector out of the Split mode.

Note: If no split point is defined, the factory setting of G2 will be used. The split point is not retained upon power down.

Source: PROformance Plus — emu-proformance-om (manual)