Korg Pa4X User Manual page 905

Converting notes to RX Noises
RX Noises are special ambience or mechanical sounds that allow Sounds
to be more realistic. They are usually located above C7, depending on the
Sound.
1 Go to the Global > MIDI > General Controls
2 Select the Note to RX Noise
Noises.
When this parameter is turned on, notes received from the
ports, or performed by the internal Players, in the RX Noises range, are rec-
ognized and converted to RX Noises.
This parameter is automatically activated each time the instrument is turned
on.
Connecting MIDI devices |891
page.
checkbox to convert incoming notes to RX
MIDI IN or USB