Reviewing Logic Pro X’s Compressors (Are They Any Good?)

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  • 7 different compressors in one, but are they any good?
  • Familiarize yourself with each of Logic’s compressor models.
  • Make bold sounds without expensive third-party plugins.

Image: apple.com

What Is Logic’s Stock Compressor?

Simply named “Compressor”, the stock compressor in Logic Pro X is a standard AU plugin that is included when you purchase Logic Pro X.

Often, we producers are encouraged to resort to third-party VST compressor plugins. These can be expensive (but don’t have to be, check out out favorite free compressor plugins here), especially if you’re looking at top-of-the-line hardware modeled compressor plugins with extra warmth and color. While our DAW’s stock tools are great for mixing, they are often designed to be “transparent”, so won’t add any extra sonic mojo.

A lot of users don’t realize the good news: Logic Pro X has already included beautiful-sounding models of famous analog compressors for you to play with!  

If you want to master compression with just the stock plugins, we’ve got you covered. We’ll take you through the different compressor models packed into this one plugin, and even give you a little creative advice on what to do with each model.

If you’re not sure where to find Compressor, choose an audio or instrument track, add a plugin, and look under the “Dynamics” sub-menu.

(Note that this is a mono track.)

What Is Compression For?

There are many uses for audio compression and other dynamics processors. A compressor can be used to even out the level of an individual track, or it can add bite, color, crunch, or creative effects to otherwise simple instruments.

This is particularly true when dealing with plugins that are modeled on vintage hardware as often the coloration they add to the signal is more desirable than the compression itself.

The Controls

First, a refresher. Let’s get our heads around the basic controls of the Logic Pro X Compressor.

You’re probably familiar with the standard controls of a compressor by now, but Logic’s Compressor plugin is really quite a rich suite of compression tools. This means you might encounter new controls or discover something new about controls you are already familiar with.

Threshold

Threshold is simply the level at which the compressor will start to react to your audio track. Turn down the threshold, and you’ll see the needle pop more often (this is the gain reduction). The compressor will be triggered to reduce the audio signal any time the input goes over the threshold.

Turn the threshold up, and the compressor will do less work, only reacting and reducing the level of your track when the signal gets loud.

There’s no single setting here that will work best, it all depends on what sort of compression you are after. If you want some gentle automated reduction on the peaks of your audio track, a high threshold is advisable. If you want a more affected and thick sound, you might want to set it low so that the compressor works much harder.

Tip: A lot of producers will recommend using two compressors in a chain, one with a high threshold to capture the peaks, then another with a lower threshold to add overall level consistency, sustain, or body to the audio layer.

Ratio

The ratio is the amount by which the level will be reduced when your input signal exceeds the threshold. A high ratio understandably means more compression.

You can think of the ratio as setting the “strictness” of the compressor.

The ratio is expressed as a proportion of the input level to the output level. So a setting of 2:1 means that a signal that is two decibels over the threshold will be reduced by one decibel, and a signal that is eight decibels over will be reduced by four.

A compressor with a high ratio is also known as a limiter as signals crossing the threshold are strictly reduced, effectively making the threshold the volume “limit”. For more on this, check out Compression Vs Limiting: What’s The Difference?

Makeup

Makeup is a handy gain control that lets you bring up the overall level of the compressed signal. Because compression is by definition a “reduction” in level, the makeup gain helps you compensate and bring the track back up to its intended volume as you work.

Ideally, the makeup gain should match the gain reduction so that when the effect is bypassed the maximum signal level stays the same. The compressed signal will sound louder but should be using the same amount of headroom.

Knee

Next, Knee is how harsh or gentle the compressor acts on the input signal. In a broad sense, it changes how the compressor reacts as the signal approaches the threshold. A “soft” knee setting will start to apply gentle compression even before the threshold is crossed, but a “hard” knee is more strict and will only react once the threshold is breached.

Generally, this is quite hard to hear. Really it has a subtle effect on the overall character of the compression. So play with this and trust your ears. Whatever sounds good for your track is the best setting.

Attack and Release

Attack is an essential parameter to get in and play with, as it controls the length of time before the compressor acts and reduces the level of the input signal.

You can set it very low for an “unaffected” sound, or you might want to set it somewhere between around 40 – 80 milliseconds to add an extra “attack” each time the input signal strikes above the threshold.

It’s good practice to leave at least 10ms for transients to pass through unaffected. If we squash the transients with the rest of the sound, we lose punch and impact.

Likewise, Release is the amount of time it takes for the compressor to ease off and stop working each time it hits. In most cases, you want the compressor to fully reset before the next transient hits, so it’s common to match the release time with the tempo of the project with this in mind.

To save you the trouble, you can use the Auto release mode, which is a reliable way of ensuring that compression is being safely applied. However, this will give you less control over any “pumping” effects you can otherwise do with a manual release time.

Other Controls

Without going into too much detail, the remaining controls are:

  • Mix – Mix the dry signal in with the compressed signal, allowing for parallel or “NY” compression.
  • Distortion – Add more color and character to your sound.
  • Limiter – Applies a quick-and-easy limiter to the compressed signal, allowing you to trim out peaks.
  • Gain Reduction – This is a meter, not a control. It shoulds how much compression is being applied to the signal and is useful for making mixing decisions.
  • Sidechain –  Uses the level from another track to activate the compression on this track, creating characteristic “ducking” effects.
  • Auto-gain – This attempts to match the compressed signal’s level to the level of the dry input signal.

And then of course there are the Mode buttons up top, which change how Compressor processes incoming audio by emulating different classic hardware units. We’re going to take a closer look at this now as it’s one of the coolest things about Compressor…

7 Compressors In One – Logic’s Compressor Types Explained

Did you know that the team at Apple spent some serious energy on giving you a great range of compressors in one package with Logic Pro X? Not only that, but these different compressors each have a unique real-world counterpart that has been painstakingly recreated.

The good news? They’ve done a fantastic job! Let’s go over them for you.

Platinum Digital

Named after an earlier release of Logic (Logic Platinum, circa 2003!), Platinum Digital has been around since version 5 of Logic, and is a straightforward “digital” compressor.

This compressor has a transparent sound (it doesn’t change the “timbre” or color of the layer at all), and its purpose is simply to modify the level of the input signal in real-time, based on the settings that you choose.

Producers tend to use Platinum Digital when they need to make some technical adjustments to the way the level, the attack, or the release of a sound behave. 

A very handy plugin, but let’s look under the hood a little more of Logic’s Compressor and check out what other powerful secrets lay hidden!

Studio VCA

Yep, the “red one”! Studio VCA is an incredibly warm and “friendly” sounding compressor. It’s absolutely beautiful for adding a bit of soul to software synths, which can otherwise tend to sound a little cold.

Modeled on the real-world Focusrite Red 3, this compressor can also be handy on the master channel of your track to add warmth and body if that’s what you’re going for. As with everything, don’t overdo it, or you’ll just get audio mud!

Image: reverb.com

Tip: Studio VCA comes into its own on an instrument or vocal layer when you push the Threshold down and choose one of the Distortion options. Have a play, and enjoy the warm flavor of this compressor.

Studio FET

The “attack monster”, Studio FET is brilliant on lead sounds, particularly if you’ve recorded a hardware synth and you want it to strike you right in the middle of the chest!

Based on its real-world counterpart, the UREI 1176 the Studio FET (Field-effect Transistor) compressor is designed to give you a responsive and punchy attack, as well as providing a bit of nice color to the overall sound.

Adjust the threshold, ratio, and attack to find the sweet spot for a layer you’re wanting to get the most out of.

Tip: Give your lead part a solid attack to help find its place in the mix. The attack will poke through your mix and allow you to nestle the layer deeper in with the rest of the instruments, just biting through every time the compressor is initially activated.

Classic VCA

The simplest of them all, the Classic VCA is modeled on the sound and controls of the real-world dbx 160.

Notice there are no attack and release controls here. The simplicity will help you make quick decisions, as you set the threshold and ratio to find the sweet spot.

It’s recommended that you try this compressor on drums, as it will provide a little bit of character while “gluing” the kit together sonically.

Side Note: The boffins over at Universal Audio have also released an emulation of the dbx 160. You may want to compare it with the stock Logic Pro X plugin.

Vintage VCA and Vintage FET

Just to keep it simple for you, these are even warmer, even fuzzier versions of the Studio VCA and Studio FET models. Once again, they are designed with real-world counterparts in mind.

Vintage VCA is based on an SSL bus compressor, and Vintage FET is another 1176-type compressor.

Vintage Opto

A real treat to cap off this powerful collection of compressors, the Vintage Opto is based on the sound and behavior of old “optical” compressors. If you want to get a very smooth compression effect, while still coloring the sound with warmth and richness, Vintage Opto is the way to go.

Try Vintage Opto when you want to let mid and low frequencies sing through, while higher frequencies are more finely attenuated.

Fun Fact: Optical compressors literally react to a light flashing in response to the audio signal coming in. They have a bit of a sluggish response once all the conversions are factored in, resulting in their distinctly smooth vintage tone.

Some Advice to Finish

The bad news is that a compressor will almost never fix a weak sound. Compression is intended to either bring out the best in your sounds, eliminate inconsistencies, or provide a tool for experimentation.

The good news is that Logic Pro X comes with a very solid and convincing range of compressors with a wide variety of uses. As always, have a play around, trust your ears, and enjoy your music making!

If you’re interested in learning more about compression, these articles are essential reading: