What Is A De-esser?

By Richard Pryn •  Updated: 04/26/22 •  7 min read

What is a de-esser and how do you use it to get a clear and polished sound on your vocals when recording?

The term “de-esser” has been around for decades, but the technology behind it was only recently developed in the late 1980s by engineers at Sony Music Studios in New York City.

What Is A De-esser?

The first commercially available de-essers were designed by engineer/producer Bob Clearmountain, who used them extensively on his recordings with Michael Jackson, Whitney Houston, Tina Turner, Mariah Carey, and more.

The core role of a de-esser can be found in the name. It gets rid of excessive “S” sounds. You can essentially think of it as a pop guard for sibilance.

Where pop guards keep that pesky “P” consonant on a leash, a de-esser is capable of keeping sibilant sounds such as “S”, “Sh”, “Ch”, “Z”, and “J” under control.

The de-esser works by removing unwanted high frequencies from a vocal track using an electronic circuit that replaces these frequencies with lower ones.

This process can be done either before or after the original recording has been mixed down into its final form.

How Does A De-esser Work?

There are two basic types of de-essers: analog and digital. Analog de-essers work by replacing the unwanted frequencies with a different frequency that sounds like the original one.

Digital de-essers take advantage of computer processing power to replace the unwanted frequencies with other frequencies that sound similar to the original one.

Both types of de-essers have their advantages and disadvantages.

A de-esser consists of two main components: a compressor and a limiter. The compressor reduces the dynamic range of a signal, while the limiter increases it.

Together they create a perfect balance between the loudness of a signal and its clarity.

A typical de-esser setup looks like this:

De-esser Compressor Limiter

The compressor compresses the volume of a signal so that any peaks are reduced, and the overall level remains stable. The limiter then boosts the level of the compressed signal back up to the original level.

In other words, the limiter makes sure that there is no clipping (excessive amplification) of the signal.

When the compressor is set to maximum compression, the limiter will boost the signal as much as possible without causing distortion.

When the limiter is set to maximum gain, the compressor will reduce the signal as much as necessary to keep the overall level constant.

When the compressor is set to minimum compression, the limiter won’t boost the signal as much because the compressor already removed all the peaks.

When the limiter’s gain setting is at maximum, the compressor won’t compress the signal enough to make it quieter than the original level.

As mentioned above, the de-esser can work either before or after the mixdown. If the de-esser is placed before the mixing stage, the compressor and limiter will operate on the entire song.

However, if the de-esser is added after the mixdown, the compressor and limiter will operate on just one instrument at a time.

Why Use A De-esser?

There are many reasons why you might want to add a de-esser to your studio. Here are some examples:

  1. To increase the clarity of a vocal track
  2. To reduce the amount of noise produced by a microphone
  3. To improve the quality of a drum kit
  4. To reduce the amount or frequency of feedback caused by a guitar amp
  5. To eliminate the need for a compressor during overdubbing
  6. To reduce the amount and frequency of reverb applied to a room
  7. To remove the harshness of a distorted sound
  8. To reduce the amount, frequency, and duration of a cymbal crash

How To Use A De-esser: Dos And Don’ts

If you’re a new user, we recommend that you start with the basic de-esser. The de-esser is an essential tool for anyone who wants to master their technique.

What Is A De-esser

Here are some dos and don’ts when working with a de-esser:

Get To Know Your Equipment

Before adding a de-esser to a song, get familiar with what each component does. Learn how to use them properly. You should also understand how they interact with each other.

Know Your Settings

It may seem obvious, but it bears repeating. Make sure you have the correct settings selected on both the compressor and the limiter.

Understand The Difference Between Peak Reduction And Limiting

Peak reduction refers to reducing the amplitude of a waveform. This means that the peaks of the waveform are lowered, which reduces the dynamic range of the audio signal.

Limiting refers to boosting the amplitude of a waveform. This increases the dynamic range of the signal while maintaining its shape.

Practice

The best way to learn how to use a de-esser is to practice. Play around with different settings until you find something that works well for you. Once you’ve mastered the basics, try using a de-esser on a real project.

Keep It Simple

The more complex the setup, the harder it will be to control. Try to keep things simple. If you’re having trouble getting the results you want, simplify your setup.

Experiment

Don’t limit yourself to only one type of de-esser. There are several types available including parametric, graphic, and analog. Each has its benefits and drawbacks.

Try out different models until you find the one that suits your needs. This is something you should do once you have gotten to grips with the above, mainly ‘keeping it simple’.

Check Your Gain Structure

De-essing usually lowers the overall level of the audio signal. This means that any subsequent processing (compression) will affect the volume of the recording.

If this isn’t taken into account, there could be problems. For example, if you record vocals over a kick drum, the de-essing process can lower the overall volume of the mix.

As a result, the kick drum won’t be as loud as it would normally be.

To avoid this problem, make sure that the gain structure of the track is set correctly before applying the de-essing effect.

Avoid Saturation

When working with a de-esser, you should always monitor the output of the device. Saturation occurs when the input signal exceeds the maximum capacity of the device.

This causes distortion and noise. In extreme cases, the sound becomes unusable.

When setting up your de-esser, make sure that the input level doesn’t exceed the maximum capacity of the unit.

Use The Right Amount Of De-essing

There’s no point in applying too much de-essing. Too much de-essing removes all the detail from the source material, making it difficult to hear.

On the other hand, not enough de-essing makes the source material sound harsh or unnatural. To achieve the desired effect, play about to try to apply just the right amount.

Don’t Forget About The Master Bus

If you don’t de-ess the master bus, then the de-essing process will also affect the volume levels of the individual tracks. This can cause unwanted changes in the balance of the mix.

If you need to de-ess an entire song, consider adding a de-esser plug-in to the master bus.

Final Thoughts

A de-esser is a great bit of kit to use for improving the quality of recorded music. It can help to remove excessive sibilance and unwanted noises such as clicks, pops, and hums.

However, it shouldn’t be used indiscriminately. You’ll need to experiment to get the most out of it, but that’s half the fun!

Hopefully, this article has given you a little bit more of an understanding about de-essers and the processes used to create more selective and purer toned sounds. 

Richard Pryn

Hey there. I am an award winning composer for movie trailers, including Bladerunner 2049, Diablo II, WandaVision, and loads more. I am the founder of The Trailer Music School where my aim is to teach everything I know about music composition, production, and generally being a functional human being. I podcast, blog, vlog and jog (sometimes). I also love coffee, nachos and self-improvement. I live with my wife, three kids and numerous pets. I am also known by my pseudonym, Richard Schrieber (it’s a long story).

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