Alesis QuadraSynth Plus Reference Manual page 43

Overview: Chapter 4
Each bar graph indicates a parameter's approximate value—increasing a
value increases the column height. With bipolar values that can go
positive or negative, turning a knob clockwise increases the column
height upward from the midpoint, and turning a knob counterclockwise
increases the column height downward (more negative value) from the
midpoint.
Always refer to the parameter name strip in the display above the
bargraphs for the current parameter label and value.
QuadraSynth Plus Piano Reference Manual 44