Pliant Crewcom CCU-22 Operating Manual page 63

G. Intercom Audio In/Out: The IN level control adjusts the incoming level (from the connected wired intercom)
of the currently selected wired intercom channel. If an intercom port is disabled, the IN Level control is inactive.
The default setting for 2-Wire Intercom In is "−6." The default setting for 4-Wire Intercom In is "0."
The OUT level control adjusts the outgoing level (from CrewCom) of the currently selected wired intercom
channel. If an intercom port is disabled, the OUT Level control is inactive. The default setting for 2-Wire
Intercom Out is "+4." The default setting for 4-Wire Intercom Out is "0."
Figure 29 Intercom Type Options
Operation - 55