If you’re a seasoned pro, this guide isn’t for you, but you’re welcome to check my work, lol. For those starting out in music production, you probably are wondering what to do with the compressors. I was in the same boat starting out. It took me a while to figure out how, what, where, and why.
You may have noticed that you already have some in your plugin folder. Logic Pro, Cubase, Pro Tools, etc., all have several different types of compressors. If those aren’t enough, you might consider buying additional plugins from 3rd party developers.
In this post, we’ll cover why you want to use them and the available types. We’ll also explore how to use compressor plugins effectively. Conversely, we’ll look at alternatives to compression that can achieve similar effects. So let’s get started.
What is a Compressor Plugin?
A compressor plugin is a software effect that mimics the behavior of a hardware compressor. Compressors work by reducing the dynamic range of an audio signal. The goal here is to minimize the difference between the loudest and quietest parts of the signal. This can be useful for controlling the level of a track. Additionally, it can bring out the details in a mix and add character and color to a sound.
A compressor plugin typically has four main components:
- Threshold: This controls the level at which the compressor reduces the signal volume.
- Ratio: This controls the amount of gain reduction applied to the signal once it crosses the threshold.
- Attack: This controls how quickly the compressor kicks in once the signal crosses the threshold.
- Release: This controls how quickly the compressor lets go once the signal drops below the threshold.
Types of Compressor Plugins
- VCA (Voltage-Controlled Amplifier) Compressors: These are fast and transparent compressors commonly used on drums, bass, and vocals.
- Optical Compressors: These are slower and more colorful compressors often used on guitar, bass, and vocals.
- FET (Field-Effect Transistor) Compressors: These are fast and aggressive compressors commonly used on drums and bass.
- Tube Compressors: These are warm and rich-sounding compressors often used on vocals, acoustic instruments, and mastering.
Why Do You Need to Use Compressors?
Compressors have many practical applications in music production and audio engineering. Here are some of the most common reasons why you might use a compressor:
- Control dynamics: Compressors are often used to tame dynamic range by reducing the level of louder parts of a signal. Simultaneously raising the level of the quieter parts. This can be particularly useful when mixing multiple tracks together. The end result is a more balanced and cohesive sound.
- Increase sustain: Compressors can also be used to increase the sustain of a sound. By reducing the level of the initial attack, a compressor can allow the sustain to come through more prominently. In essence, a more full-bodied sound is achieved.
- Add character: Depending on the compressor used and how you set it up, it can add character or tone to the sound. For example, some compressors are known for their warmth, while others are known for their transparency or aggressiveness.
- Glue tracks together: Compressors can also “glue” tracks together, creating a more cohesive and unified sound. This is often done using a bus compressor, which simultaneously applies compression to multiple tracks.
In terms of when to use compressors, it really depends on the specific application. In general, though, compressors are often used during mixing and mastering to shape the dynamics of individual tracks and the overall mix. They can also be used during recording to control the level of individual instruments or vocals.
Where Should You Place the Compressor?
The placement of a compressor depends on the specific application and the effect you’re trying to achieve. Compressors can generally be placed on individual tracks, buses, or the master bus.
Here are some common scenarios where you might use a compressor on different parts of the mix:
Individual tracks: Compressors can be placed on separate tracks to control the dynamics of that particular instrument or sound. For example, use a compressor on a vocal track to even out the level and make it sit better in the mix or on a guitar track to add sustain and create a more consistent level.
- Busses: Compressors can also be placed on buses, which combine multiple tracks into a single channel. For example, you might use a compressor on a drum bus to glue the individual drums together and create a more cohesive sound or on a vocal bus to bring out the lead vocal and make it more prominent in the mix.
- Master bus: Finally, compressors can be placed on the master bus, which applies compression to the entire mix. This can be useful for shaping the overall dynamics of the mix and creating a more polished, cohesive sound. However, it’s essential to use caution when applying compression to the master bus. The result will cause over-compression on the entire mix, causing a lifeless feeling.
Ultimately, the placement of a compressor comes down to the specific context and the desired effect. Using your ears and experimenting with different placements is essential to find the best approach for your situation.
Compressor Plugins in DAWs
Most DAWs come with at least one compressor plugin, and some come with multiple options. Here’s a breakdown of the compressor plugins with Logic Pro X, Ableton Live, Cubase, and Studio One.
- Logic Pro X: Logic Pro X comes with several compressor plugins, including the classic Platinum Digital and vintage LA-2A, LA-3A, and 1176 emulations. Logic Pro X also includes a versatile multi-band compressor, which allows you to compress different frequency bands independently.
- Ableton Live: Ableton Live has several compressor plugins, including the classic Glue Compressor, which is explicitly designed for mix bus compression. Ableton Live also includes a versatile multi-band compressor and a sidechain compressor, allowing you to use one audio signal to control the gain reduction of another.
- Studio One: Studio One comes with several compressor plugins. The Fat Channel XT is modeled after vintage analog gear. Studio One also includes a versatile multi-band compressor, a sidechain compressor, and a dynamic EQ.
Third-Party Compressor Plugins
While most DAWs come with at least one compressor plugin, many producers and engineers prefer to use third-party options. Here are some of the biggest third-party manufacturers of compressor plugins, along with some of their most popular choices.
- Waves: Waves is one of the biggest names in the world of audio plugins, and they offer a wide range of compressor plugins for all types of applications. Some of their most popular options include the SSL G-Master Buss Compressor, the CLA-2A, and the API 2500.
- Universal Audio: Universal Audio is known for its high-quality hardware emulations, and they offer a wide range of compressor plugins modeled after classic analog gear. Some of their most popular options include the LA-2A, 1176, and the Fairchild 670.
- FabFilter: FabFilter is known for its modern and intuitive interfaces, and they offer a wide range of compressor plugins designed for mixing and mastering applications. Their most popular options include the Pro-C 2, the Pro-MB, and the Pro-L 2.
Should You Even Be Using Compression?
While compressors can be handy tools in music production, they may not always be the best choice. Here are a few scenarios where you might want to avoid using a compressor:
- It’s best to avoid using compression while recording unless you have a specific reason. Compression should be used as a non-destructive effect, applied after the fact. If using it during recording, it can’t be undone. Additionally, suppose you apply too much compression while recording. In that case, you may end up with an overly compressed sound lacking in dynamics.
- While compressors can be valuable tools during mixing, using them judiciously and only when necessary is essential. Too much of a good thing can lead to a lifeless, dull track. Alternatively, applying too little compression can result in a mix lacking cohesion and dynamics.
- Compression is often used during mastering to shape the overall dynamics of the mix. That said, it’s essential to use it carefully and sparingly. Over-compression on the master bus will cause punch and dynamics to suffer.
It’s important to use your ears and experiment with different settings to find the optimal amount of compression for each track and the overall mix. It’s also important to remember that compression is just one tool in the audio engineer’s toolbox and that other techniques and effects can often be used to achieve similar results.
Alternatives to Using Compression
Several techniques and effects can be used instead of, or in conjunction with, compression to achieve a pleasing effect in music production and audio engineering. Here are a few examples:
- Volume automation: One alternative to compression is to use volume automation to manually adjust the level of a track or section of a track. This can be useful for controlling performance dynamics without introducing compression artifacts.
- EQ: Equalization (EQ) can be used to shape the tonal balance of a track or mix. You can create a more balanced and polished sound by boosting or cutting specific frequencies.
- Saturation: Saturation is a type of distortion that can add warmth and richness to a track or mix. The addition of more harmonics makes for a more analog mix.
- Parallel processing: Parallel processing involves duplicating a track, applying different effects to each version, and then blending them. This can be useful for achieving a more complex and exciting sound without overcompressing the track.
Multi-band compression: Multi-band compression is a type of compression that applies different amounts of compression to various frequency bands. This can be useful for controlling the dynamics of a track without affecting the tonal balance.
Experimenting with different techniques and effects is essential to find the best approach for each situation. While compression can be a powerful tool, it’s not always the best choice, and other techniques and effects can often be used to achieve similar results.
Using Sidechain Compression
One advanced technique often used in electronic dance music is sidechain compression. This involves using a separate track, such as a kick drum or a bassline, to trigger the compression on another track. The result is a pumping effect that enhances the rhythm and groove of the mix.
What you are going for here is that you want the bass to duck out of the way of the kick drum each time it hits to create a more pronounced and rhythmic groove. You would apply a compressor to the bass track and set the sidechain input to the kick drum track to achieve this. This would cause the compressor to reduce the level of the bass track each time the kick drum hits, creating a rhythmic pumping effect.
Sidechain compression can be used in various ways to create exciting and dynamic effects in a mix. However, it’s essential to use it judiciously and not overdo it, as too much sidechain compression can result in a sound that’s overly processed and lacking in dynamics.
Here are a few tips for using sidechain compression effectively
Use it sparingly: Sidechain compression can be powerful, but it’s essential to use it judiciously and only when necessary. Overusing sidechain compression can result in a sound that’s overly processed and lacking in dynamics.
- Set the threshold and ratio carefully: When applying sidechain compression, it’s essential to carefully set the threshold and ratio to achieve the desired effect. A lower threshold and higher ratio will produce a more pronounced pumping effect. In comparison, a higher threshold and lower ratio will result in a more subtle effect.
- Choose the right source: The source track you use to trigger the sidechain compression can significantly impact the resulting sound. Experiment with different sources to find the one that works best for the effect you’re trying to achieve.
- Use EQ to shape the sidechain input: If the sidechain input is too busy or contains frequencies competing with the track you’re compressing, you can use EQ to shape the sidechain input and isolate the frequencies you want to trigger the compression.
- Automate the sidechain input: Sometimes, you can automate the sidechain input to create a more dynamic and varied effect. This can be useful for creating complex rhythms and patterns that evolve over time.
In situations where sidechain compression shouldn’t be used, it’s a matter of personal preference and the specific requirements of the mix. However, it’s essential to use it judiciously and not overdo it, as too much sidechain compression can result in a sound that’s overly processed and lacking in dynamics.
Additionally, suppose the source track you’re using to trigger the compression is too busy or contains frequencies competing with the track you’re compressing. In that case, it may be better to use a different technique or effect to achieve the desired result.
Compression was something that took my time to understand. Compressor plugins are an essential tool in the recording, mixing, and mastering process, used to control the dynamic range of audio signals and add character and color to a mix.
Understanding the different types of compressors available and how and when to use them can help you achieve the desired sound for your project. With some trial and error, you will figure out what sounds good and what doesn’t.
And don’t forget, there are alternatives to compression that can achieve similar effects, and it’s essential to know when not to use compression and when to use advanced techniques such as sidechain compression.
If you are still confused about how compressors work or have something to add, leave a comment!