Muting a Sound System During a Fire Alarm

In public buildings it is often required that sound systems be muted during a fire alarm. The installer of the fire alarm system will generally provide the installer of the sound system with a set of dry relay contacts to initiate a sequence of control that is, hopefully, well defined in the project specifications and acceptable to the Local Authority Having Jurisdiction (AHJ = Fire Marshal). One method of muting the sound system is to interrupt the audio signal between the output of the mixer / processor and the power amplifier inputs. The ST-SSR1 2 X 1 Line-Level Audio Switch can be readily controlled by the fire alarm system Normally Open or Normally Closed dry contacts and will provide solid-state ON / OFF switching of the audio signal without the POPS and TICKS associated with mechanical contacts. The ST-SSR1 can also be used to mute the normal audio source and select a line-level feed from the fire alarm system to supplement the evacuation system. Always seek and receive the approval of the Local AHJ before installation of any system interfaced with a required fire alarm system. Requirements will vary between jurisdictions.