A noise gate is generally a tool for making and recording music by removing unwanted noises.
While learning music production, I came across the term "noise gate."
At first, it seemed very simple and unimportant, but I understood its importance as I continued my journey.
This article will also help you understand how important it is. Additionally, you'll learn exactly what a noise gate is, how to use it, and when to use it.
What Is a Noise Gate?
The noise gate's job is to process the audio, removing unwanted noises while retaining the desired sound. A plugin or pedal usually does it.
The noise gate will mute every sound below a specific volume you set, and you will hear the rest.
Here is an example graph of the idea:
Every noise in the red area below the Noise gate (Gate) in the graph will be reduced, usually to 0dB, and with this process, you can achieve cleaner and better mixes for recordings.
You can easily remember the concept by imagining an actual gate that you can only come through if it's opened.
How Does the Noise Gate Work?
As I wrote above, the concept of the noise gate is very straightforward.
It works on a threshold that you set; every sound above the threshold passes through, while the threshold blocks every noise below it.
The noise gate plugins usually come with five main parameters, while the pedals have fewer:
The first main parameter is the threshold, the level you set to let the sound pass through. This parameter is the most important and will be on every plugin and pedal.
You can set the threshold just by hearing and looking at the meters.
The following parameter is the ratio, which determines the amount of volume reduction on the audio. So, you can choose to keep the amount of gated sound below the threshold.
You can choose to use the ratio to make your signal cut sharper or less sharp.
The attack is how fast the gate works and opens after the input level goes above the threshold.
Usually, I would go with fast attack time, but you can play with it as you like and for your specific needs.
The release determines how quickly the gate closes after the level falls below the threshold level.
Open gate means sound pass.
Close means sound attenuated.
The hold is for how long you want to hold the gate open after the level passes below the set threshold.
*Some parameters can act differently on different plugins.
Don't use the parameters aggressively and listen carefully for the best results.
Some plugins would have visual indicators but always stick to the sound with music.
Difference between The Noise Gate and The Compressor or Limiter
The difference is straightforward. The compressor is made to reduce everything above the threshold, make the sound balanced and make the lower parts louder, while the noise gate is used to reduce the sound below the threshold.
(This type of noise gate is also called an expander).
The limiter is an extreme compressor case that will mute everything above a chosen threshold.
Using the noise gate to absolutely mute sounds below the threshold is the opposite of the limiter.
(This type is called a gate, and it's an expander with an infinite ratio).
When To Use the Noise Gate
Learn where to put noise gate in a signal chain when mixing.
Some reasons to use the noise gate may be obvious, and some not.
The first desirable use of the noise gate is when you record, and you can hear some stuff going on in the background.
It could be just the singer moving; the mic gets a little bit of sound from the headphones (if you use open-back headphones, this problem may become noticeable), the sound of your pc fans, the air conditioner, or just the sound of traffic that gets in from outside, a knock on the mic, breathing noises, and every little noise that recording can make.
Of course, there could be more situations, but this is the main idea.
Another reason to use the noise gate on recordings is to create more natural silences instead of just cutting them.
Even with a noise gate, every recording will keep some noise, but you can make it much better.
To get more specific, the examples of when to use a noise gate in vocals are to get cleaner separations between the singing, when the singer takes a breath or just being quiet, you want to clean the air, or the headphones bleed in the background, and as I mentioned above, it keeps the recording more natural.
With the vocals, you don't want to remove all the breaths in between because you want to keep a human aspect in them.
Another thing to remember regarding vocals is to take your time getting the proper parameters (threshold, attack, release, etc.) so you don't accidentally cut the end of sentences.
Sometimes overprocessing and setting the parameters incorrectly (too much) might result in further difficulties, such as choppy vocals, and it will not clean the thing you want.
A rule of sense of using noise gate on vocals is to use it after you have already set other mixing plugins in the signal chain (but before the reverb and the delay) to make the noise that wasn't audible before noticeable.
Some noise gate plugins offer a preset specifically for vocals, and you can first use it and then change the parameters to your will.
As for the vocals, various reasons could lead you to use a noise gate, and it also depends on how you use, record, and the type of effects on the guitar. But to give you an example, a screeching sound or if you are using an electric guitar with an amp set to a higher gain and then adding a treble booster pedal, there will be an unwanted noise that can be rid of with a noise gate.
Sometimes, when you still hear the noises while the instrument plays, you should use other solutions like a noise remover plugin.
The noise gate can be placed with guitars before setting other mixing plugins in the signal chain.
If your sample has an unwanted sound, you can often use the noise gate to reduce or remove it from the sample (if the sound is lower than the other elements).
With recording drums, depending on the room, you may want to use a noise gate to get rid of the room reverb or the room atmosphere and more reasons the same as for recording a guitar or a vocal mentioned above.
And with the drums, the noise gate can be placed before you set other mixing plugins in the signal chain.
When placing the noise gate in the mixing chain, it is not always black and white so try to experiment with it.
How To Use the Noise Gate in Practice?
The example shown is a sample of an entire drum loop in which you want to side chain only the kicks out of him quickly with the help of a noise gate plugin.
First, I'll use a random full drum loop and a random instrument for this example.
Next, you send the full drum loop signal to another channel in the mixer(Picture on the left).
Now you go to the routed channel (channel 2, Picture on the right), remove the routing from it to the master and add a sidechain routing to the random instrument channel; in our case, channel 3
Now, in the random instrument channel, you add the sidechain plugin and adjust the settings for the sidechaining.
As you can see, the stock limiter plugin in this software also comes with a noise gate.
Now the problem is that you are also sidechaining the hi-hats and not only the kicks from the loop.
So, you need to add an equalizer to channel 2 and remove the frequencies of the hi-hats.
Although the sidechaining will now be cleaner than before, some noises still interfere.
And now the noise gate comes in handy.
To get the best and cleanest side-chaining, add a noise gate plugin to channel 2 and adjust the parameters to eliminate unwanted noise.
Thanks to the noise gate, you have the cleanest sidechain you could get.
Pro Tip: sometimes, if the kick is four on the floor, the only thing you need is a sidechain plugin.
A noise gate is an excellent tool for recording, mixing, and fixing unwanted noises.
Although it's not in the spotlight, it's an essential tool for your music journeys like the compressor and the limiter.
The concept is easy and has a lot of practical uses.
Remember to use it when you need it, and don't abuse it on every channel. If you utilize this tool appropriately, it can greatly improve your recordings.