The setup panel is used to set volume levels, EQ settings, etc.
The four sections are:
a) Volume & EQ
b) Equalizer
c) Bus Sends
d) Main Bua
In detail:
This panel controls the volume and pan of the main output bus, setting overall volume and left-right pan. The Mono Bus button switches between Stereo and Mono. Generally you will set this to be Stereo