The following example illustrates the inner workings of the backup amplifier concept.

Loss of speaker lines

No announcement in the case of an alarm

  1. Plan the backup amplifier concept for each amplifier within the system.

The following example can only compensate for a fault on a single amplifier. Any further faults will result in the loss of speaker lines.

  • 2x 'Digital audio matrix (4/4/16)'
    • 1x backup master
    • 1x device
  • Two amplifiers are connected to each 'Digital audio matrix (4/4/16)'.
  • Each amplifier has two audio channels.
    • E.g., power amplifier 2x250 W
  • Inner workings of backup amplifier concept
  • The amplifiers (1) are used for background music and announcements.
  • The backup amplifier (2) is activated when the system detects a fault.
  • All amplifiers are constantly monitored via a pilot tone.
  • The 100 V signal (3) of the backup amplifier is connected to all 'Digital audio matrix (4/4/16)' backup inputs in the same backup configuration.
    • This wiring is also monitored by all 'Digital audio matrix (4/4/16)'.
  • A pilot tone is used to monitor the speaker lines (4) too.
Example of a backup amplifier concept: Typical fault

The figure above shows a typical fault in a system. One channel on the amplifier (1) fails (red). After several seconds, the 'Digital audio matrix (4/4/16)' detects the error and reports it to the backup master.

If no other errors were reported previously, analog audio outputs 3 and 4 of the backup master take over the audio function of analog audio outputs 1 and 2 of the 'Digital audio matrix (4/4/16)'.

The backup amplifier (3) amplifies the analog audio signal to 100 V and transmits it to all 'Digital audio matrix (4/4/16)' connected in the backup configuration.

The relay matrix of the 'Digital audio matrix (4/4/16)' toggles from the regular 100 V inputs to the 100 V backup input (4). The speaker lines (5) connected to the amplifier (1) are now operated by the backup amplifier (3).