An often overlooked dynamic processor is the noise gate. Basically, a noise gate (or gate for short) is normally used to keep out any unwanted noise like hum coming out of a guitar amp when it’s not playing, ring from toms when they aren’t being played, a click track coming through a pair of open back headphones while recording a vocal track, etc. You can set it up so it allows only the desired sound to pass through, “gating” the rest.
It works by setting a threshold above the noise we’re trying to get rid of, but still below the sound we are trying to hear.
An Example of a Properly Set Noise Gate:
Let’s use the example of speech recorded in a room where noise is coming from the air conditioning vent. We set the threshold slightly above the air conditioner noise while carefully keeping it below the speech’s average level. You’ll need to adjust this to your taste and what you are trying to achieve. When the voice sound stops, and the signal drops below the threshold, the gate closes therefore rejecting the noise.
Some of the Controls on a Noise Gate Are:
Sets the level at which an input signal must fall before the gate closes.
Normally you’ll set at high values in most cases at 100:1 for it to act as a gate.
How fast the gate fully opens up.
How fast it closes down.
How long does the gate stays open.
Range (also known as Floor in some plugins such as Waves C1):
Adjust this parameter if you’d like to hear some of the unwanted signal coming through. The lower the range, the less sound the gate allows to be heard.
Besides keeping noise out, a noise gate can also be used creatively to shape transients and change a particular sound’s character. Once you have the gate controls set, change the attack and release controls and listen to how the sound responds. With a slow attack, you’ll hear something similar to a volume swell for example.