its for the velocity curve of the pads. now how do i try to explain velocity curves, eh...
it has to do with the sensitivity of how hard you hit the pads and translating that to a MIDI velocity. Basically it turns your regular linear velocity curve into a logarithmic one.
Example, say default is A, where you hit the pad with a velocity of 10, and thats what gets recorded, a velocity of ten. This would be the linear velocity curve. But logarithmic curves, when you hit with a velocity of 10, it would record ten, if you hit 20, maybe it records 30, if you hit 30, maybe it records 50. Something like that, but those aren't the correct numbers or anything.