The WTSD-PWHUB is designed to be used in conjuction with AtlasIED WTSD wall plate mixers at the head-end (amp rack) in place of the WTSD-PWBOB when additional headroom control and external device integration is necessary. The WTSD-PWHUB provides an emergency audio mute for fire systems and two NO / NC relays, one that is activated automatically by the auto sleep function and one that can be manually activated by a local latching “System Priority” button on the WTSD-MIX31K or WTSD-MIX41K. These relays can be configured to turn the head-end amp rack On or Off with the auto sleep function. The system priority button can be used to take over priority of the room by muting a background music and paging building wide system when the room is in use. The gain headroom limiter settings and indicators help control the balanced audio feed prior to the head-end amp when multiple WTSD’s are on a single bus. The limiter can be set to protect a high-power system from over loading the amplifier(s) and possibly damaging the speaker(s). 24VDC power supply required and is not included.