Sound limiter

A sound limiter or noise limiter is a digital device fitted with a microphone to measure the sound pressure level of environmental noise, expressed by the decibel logarithmic unit (dB). If the environmental noise level as measured by the microphone exceeds a pre-set level for a certain amount of time (e.g. 5 seconds), the limiter’s circuitry will cut the power supply to the musical equipment and PA system requiring the venue's staff to reset the system.[1]

Sound limiters are commonly installed at live music venues, including private venues and particularly those that host wedding receptions with live wedding bands.[2]

The visual indicator on the limiter works most commonly on a “traffic light” system: green = no problem, amber = sound levels approaching the threshold, red = threshold breached. If the light stays red for more than a few seconds, then the limiter will take action and cut the power.[3]

Sound limiters are often set quite aggressively, effectively making it impossible for some types of performance to take place without tripping the limiter, for example an unamplified drumkit may trip a limiter on its own.[4] While limiters can help reduce disturbance of other properties nearby, if set badly they can spoil live performances.

Although there is no legal requirement to install a sound limiter, they are a reasonably inexpensive piece of equipment, which can help prevent complaints as part of a sound control plan and also protect the health of staff by ensuring that the levels do not exceed those set by The Control of Noise at Work regulations 2005.[5]