Limiter

A limiter is a volume-based tool, a dynamics processor, and the last plug-in I’ll discuss in this series.

Used almost exclusively for mastering or on the master fader of a mix, the limiter is one of the simplest and most important tools for a bedroom producer to learn. Its purpose is to bring up the overall level of a final mix without allowing the peaks to clip.

Much like its cousin, the compressor, a limiter will reduce the dynamic range of a piece of audio, though there are some notable differences concerning the parameters.

First, the “threshold” of a limiter will usually be referred to as “output” and will be a number close to, but not exceeding 0 dBFS (the loudest a digital signal can get without clipping). This parameter determines the level at which the limiter will begin to compress the signal.

The “gain” of a limiter is different than that of a compressor in that it takes effect before compression. It is not intended to “make up” for what is lost through compression. Rather, it is what determines how much compression will take place by pushing the peaks closer to and ultimately over 0 dBFS.

Possibly the biggest difference between the limiter and its cousin is that the limiter has a much higher ratio (as high as 100:1), usually fixed and unable to be controlled through the use of a parameter. Essentially, a limiter cuts off the peaks, allowing the quieter parts of the audio to be brought up without clipping, raising the perceived overall volume. A limiter is most useful at the end of the mix. If the song is part of a collection, like an album or an EP, a limiter can be used to ensure that the songs all have a similar RMS level. Even if the song is a single, a limiter plays a crucial role in getting the audio up to a volume that competes with other commercial releases. A listener does not want to have to turn the volume knob between songs, whether they’re all part of a collection of one artist's songs or part of a radio stream that features different artists.