This is the time it takes for the gate to fully open once the signal exceeds the threshold level. In general, this control needs to be adjusted as low as possible (without false gate openings), since that way the original signal will be preserved. When the signal falls below the threshold level the dynamic processing starts and the gate begins to close. You may not always find all of them, or you may get additional ones. The most common controls provided on gates are given below.

The drawing below shows a noise gate (downward expander) with the most common controls. ControlsGating is a difficult task that may require very different characteristics depending of the type of signal. They just hide it by attenuating it when it is most obvious (during pauses), and let it through when it is mixed with the signal.ġ. Like for compressors, the detection circuit is extremely important, and may vary widely from model to model.Īlso, it is important to understand that gates do not eliminate the noise. Also, gates are often closed for a relatively long time. Typically, gating takes place in a slower way compared to compression (and modifies only signal RMS levels). For instance, the bass drum mic would only be active during bass drum hits, while the snare drum gate would only be open for snare hits, such that the snare does not leak into the bass drum microphone, and vice versa. The most sophisticated drum micing might use gates to avoid picking up the sound of other drums with the microphone that is supposed to pick up just the sound of a specific drum. For sound reinforcement applications gates are not as necessary since background noise is not such a big problem once the show is taking place, so gates tend to be used more with the idea of avoiding other sounds from leaking into a microphone that is not being used. For recording applications, gates are used to eliminate background noise when the instrument or voice is not generating a signal (during pauses, and just before the song starts and after the song has just finished).

There exist several reasons why a noise gate may be needed. Most gates are also able to close just partially, providing a set attenuation as opposed to muting the signal completely. The aim of a pure noise gate is to mute signals with low volume. If you haven't already, do read Introduction to dynamics processors first. In this article we'll go through noise gate control and how to use them in different applications.

Noise gates and compressors