The Gov^nor by Fitness Audio is a 1RU rack mounting Sound Pressure Level Limiter. It is usually connected between the mixer outputs and the power amplifier inputs. It can be set up manually using a Sound Pressure Level Meter to find the limiting point. The idea is to restrict the sound pressure level in a room to less than an average of 94dBA for a 1 hour fitness class, or to a lower level for a longer time.