LinPlug Organ 3 - Manual (Page 41)

Split Points & Octave
To the right of the Envelope dials are the controls for setting the manual’s
split points as well as the octave.
The one-digit number represents the octave of the respective manual. It
can be set from –4 over 0 to +4 octaves.
Beneath the octave is the split point of the according manual. It can be
set from C-2 to G8.
A split point can be set between Upper and Lower Manual, as well as
between the Lower Manual and the Pedal.
You can alter both parameters by left-clicking, keeping the mouse-key
pressed and drawing the mouse upwards / downwards.
Note: the split point between Lower Manual and Pedal has no effect in
Split-Mode 1.
LinPlug Organ 3 User Guide Page 41