The Govnor by Fitness Audio is a 1RU rack mounting Sound Pressure Level Limiter. It is usually connected between the mixer outputs and the Poweramp inputs. It can be set up manually using a Sound Pressure Level Meter to ensure that the sound pressure level in a room runs at no more than an average of 94dBA for an hour's class or dosage (noise level exposure).
Alternatively, it can be connected to a SoundEar product for a 24/7 triggered limiting action when the sound level exceeds say 94dBA for more than 8 seconds. The limiting action will let go when the volume levels are reduced below the pre-set level. It comes with a rear control security cover and the front panel shows a 2-channel display of the signal level passing through the unit.
A great solution when you are facing complaints from neighbours or councils for excessive noise/loud music.