Balanced XLR is three conductors per signal: - Pin 1: Ground - Pin 2: Signal in Phase - Pin 3: Signal flipped Two channels over XLR are done in two ways: -

Balanced XLR is three conductors per signal: - Pin 1: Ground - Pin 2: Signal in Phase - Pin 3: Signal flipped Two channels over XLR are done in two ways: - digital using the AES standard and 110 Ohm cables - analog using two balanced lines and a XLR-5 connector, although this is not an offical standard to avoid confusion with DMX