What is the difference between a compressor and a limiter? Ever heard of a leveller? In this article, we’ll give you a quick overview of all three to help make the similarities and differences clear.
A compressor acts on a signal only once it reaches a set threshold. When a signal reaches the threshold, the compressor decreases how far beyond the threshold that signal can go.
Another important setting on the compressor is the gain. Gain defines to what degree an input signal will raise in level as it is compressed. For example, a 2:1 gain setting means for every 2 decibels an input signal increases, the output signal will increase by 1 decibel.
A limiter is like a compressor acting at a very high ratio (20:1 or inifiniti:1). Like a compressor, a limiter only acts on a signal once it reaches a set threshold. Unlike a compressor, limiters prevent (or limit) a signal from exceeding the threshold at all. They are able to do this because they act at such a high ratio.
Limiters vary in their ability to do this perfectly. Some have a slight delay which allows some of the signal to exceed the threshold.
A leveller also uses gain controls to adjust the level of a signal. However, instead of simply reducing the volume of the loudest parts of a track, a leveller will increase or decrease a signal in order to maintain a consistent volume over time.
Another difference is that levellers change volume slowly over time, so quick peaks or dips in signal strength might get through without adjustment.
Ok… So What Are The Differences Exactly?
To summarize, both compressors and limiters act on a signal once it reaches a set threshold. A compressor still allows a signal to raise beyond the threshold, but uses gain controls to reduce how far beyond the threshold a signal will go. A limiter on the other hand will prevent a signal from raising above the threshold at all by acting at a very high ratio. Levellers are a different story; they increase or decrease level to maintain a consistent volume over time.
The exact function of these three is a topic we’ve heard many musicians having trouble understanding. We hope this article helped clear it up for you.
If you’d like a graphic to help you remember how each one works, click the file linked below!
Is there something else about audio production that has you scratching your head? Leave us a comment below and we’ll try to help you sort it out!