Compression isn't easy to master.
It's one of the most important tools, in the toolbox, as a mixer—yet it's also one of the hardest to grasp. Focus on having a complete understanding of how every parameter works. This will get you eighty per cent of the way there.
But even then, once you have a solid grasp of the fundamentals of compression, there is still so much more to explore. So much more that could go wrong...
In this tutorial, you will learn ten vital mistakes that you might be making. These mistakes are made by mixers of all abilities. Whether you are just starting out with compression, or have been doing this for a while, you are probably committing one of the mixing sins in this list.
Not Watching the Gain Reduction Meter
Let's start with the basics. If you aren't watching the meter, you're completely missing the point of compression.
I don't like to rely on visuals too much when mixing. But this is one huge exception. The gain reduction meter shows you how hard the compressor is working. If you don't keep an eye on this, you don't know if the compressor is even doing anything.
You control the amount of gain reduction using the ratio and threshold knobs. Before you move onto advanced compression techniques, like sidechain compression, ensure you have this down.
Using Super Fast Attack Times
Once you have grasped ratio and threshold, attack time is the next thing to focus on. Compression isn't just there to control dynamics—it can also be used to change tone. This is where attack time enters the picture.
A slow attack will leave the transient of the source unaffected. This adds aggression and attack to the source. On the other hand, a fast attack will catch the transient of the note, leading to a duller, thicker sound.
In general, compression is used to make things sound more exciting and aggressive, which requires a slow attack time. But that's not all. Using a fast attack time can quickly ruin the dynamics of your music.
When in doubt, opt for a slower attack time, especially if you are using a digital compressor (like the one that comes with a DAW).
Some older analogue compressors are made to be really fast (like an 1176), but unless you are using one of these specifically, it's safer to use slow attack times.
Using Fast Release Times
The release control is perhaps the hardest one to master. At first, it seems unimportant. But in reality, it can have a drastic impact on how the compressor reacts to the source.
Fast release times have their place. Snares, kicks, fast rhythmic strumming and voice overs might require a fast release time. Often, a fast release time will make the source appear to be louder too, which is also useful in some situations.
But it is also dangerous territory. With fast release times, you can sometimes hear the compressor pumping. That's not all - fast release times can also cause distortion.
As with attack time, when in doubt, opt for a slower release.
Only Using One Compressor
When the source needs heavy compression to reign in the dynamics, it's tempting to just slam it with one compressor. After all, this seems like the obvious thing to do.
But there is an alternative—use multiple compressors in a row.
Most people refer to this as serial compression, and it's an easy, effective way to improve your use of compression. Multiple compressors working together sound better than one compressor doing all the heavy lifting.
To take this one step further, experiment with using different attack times on each subsequent compressor. Start with a fast attack time to catch the louder transients, then use a slower, less aggressive compressor to apply lighter, constant compression.
Relying on Compression Alone
Considering the upsides of using serial compression, you might think that using multiple compressors is all you need to achieve dynamic consistency.
But relying on compression alone, and not combining it with volume automation, is a huge mistake.
Let's use vocals as an example. By their nature, vocals are wildly dynamic. A vocalist can go from a whisper to a shout within the same verse. If you try to reign in the dynamics with compression alone, the vocals will sound over-compressed, dull and lifeless.
Instead, use automation to make the volume consistent between different sections. Then use serial compression on top of that to really reign it in.
Not Having an Intention
When you start using compression, you might feel like you need to use it on every channel. You don't.
Never do something just because you feel you should. Every mixing move should have an intention behind it - otherwise you are just blindly working around the mix making random adjustments.
The need for compression should come before the application.
If a guitar part that is too loud on some notes, but too quiet on others or if the lead vocal need more aggression to help it cut through the mix—grab a preferred compressor and get to work.
But don't just apply compression for the sake of it.
Not Considering Genre
Of course, there are many factors that dictate how aggressive you should be with compression. Lead vocals will always need a lot of compression to keep them on top of the mix, and low end parts—like the kick and bass—should be compressed more than other instruments.
But there there is another huge factor here that many people overlook—the genre.
Certain genres call for more compression, others for less. It's that simple.
To make rock music sound like rock music, a lot of compression is required. Even more so for heavier genres, like metal and hardcore.
On the other end of the spectrum, we have have jazz and acoustic music. These styles require little to no compression.
Bear this in mind, and use reference tracks when in doubt. Listen to a professional mix in the same genre, and take notice of the amount of compression.
Not Learning Stock Plugins
If you are struggling with compression, don't blame your tools. Stock plugins are incredible, and you don't need to upgrade for a long time.
Spend at least a year learning your stock compressor before you consider purchasing something better.
Buying too Many Plugins
When you reach the point that you notice the flaws of your stock compressor, you can make another common mistake. Buying too many plugins.
GAS, or gear acquisition syndrome, is one of the main reasons people fail. They spend too much time and money on gear and plugins, rather than honing their skills.
Buy one compressor and stick to it. Choose something that's versatile, like the FabFilter Pro-C 2 or Waves Renaissance Compressor.
Sticking to Analogue Compressors
Here's one for the more advanced mixers. It has become a common thing for people to collect a plugin emulation of every famous compressor that has ever existed.
The 1176, the LA2A, the Fairchild, the API-2500... they all sound great. But instead of looking backwards, why not look forwards.
When you learn how to use a versatile digital compressor, you can emulate the sound of each of these compressors. At the same time, you won't waste time and money on 20 different variations of analogue compressors, and you can focus on honing your skills with just the one.
In the heat of a mix, deciding which compressor to load up can waste critical time. Instead, have your go-to compressor, and stick to it.
Sure, these emulations have their uses, and I'm guilty of making this mistake in almost every mix. They are fun to use. But just consider the amount of time you could save by having just one main compressor.
Everybody makes mistakes. Sometimes, it's better to learn from your own mistakes.
But mastering compression is hard enough as it is. No need to make it any harder for yourself.
Have these mistakes in mind when you next open up a mix, and it could save you some frustration.