The SX-2000AO is an audio output of the matrix system and can be mounted in an EIA equipment rack (2U size). Multiple units can be decentralized in a whole system. It is equipped with eight audio outputs, and two inputs can be mixed and output. It is also equipped with eight control inputs, and eight control outputs. The SX-2000AO receives audio signals from the audio input unit via digital transmission, but an analog audio input function (1 channel) enables simultaneous all-zone calls for use in emergency situations. Audio output levels are indicated on the level meters provided for each output channel. Volumes can be adjusted for each channel using the volume controls on the front panel or the SX-2000 software. The volume controls can be locked. Any output channel can be monitored using the internal speaker. One control IN/OUT interface allows the number of control inputs and outputs to be increased. It is equipped with an emergency audio input and a 24 V emergency cutoff input. The SX-2000AO has two power inputs and can support a dual-redundant power supply system.