The Gov^nor Sound Pressure Limiter
The Gov^nor by AllMyAudio 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 The Trigger Loudness Monitor, also by AllMyAudio, or 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. 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.