Compression is tricky, especially for beginners. Compressors often fool people into thinking they are getting a better sound because the compressor can make sounds louder.
Louder ≠ Better
When adding compression to anything, make sure you are matching the levels of the uncompressed signal and the compressed signal to avoid getting tricked by loudness.
This section of the compression video demonstrates level matching using the track’s volume fader. The main idea is to check your meters to make sure that they are both hitting at the same level when A/B-ing the difference. More commonly, level matching is done using the make up gain in your compressor.
Hearing exactly how the compressor is changing the sound can be difficult, so in the beginning rely on your gut feelings by asking, ”Is this actually making things better or am I throwing a compressor on just because?”
If something isn’t sounding how you want, try to describe what is wrong in words. Is it too harsh? Then maybe you will want to try some subtractive EQing instead of compression…Honestly, most of the time mixing you will want to use an EQ to change the sound over any other tool besides your volume faders.
When would you want to use a compressor?
Technically, compression makes louder sounds softer and softer sounds louder, but that fact doesn’t really tell you how people perceive the difference aesthetically.
When a sound is uneven or too thin, or a mix/instrument section needs cohesion, a compressor can help.
Here are 10 ways compression can make sounds better
You have to be careful when adding compression (and mixing in general) because you might help the sound in one area but hurt it in another.
Putting on a compressor might add more fullness but suck the punchiness out of a track.
If you understand how adjusting the different settings on a compressor affect the sound, especially the attack and release, you have a better chance at finding a good balance to improve the sound.
Attack and release give the compression it’s main character. Here is a demonstration of how just adjusting the release affects a vocal.
In the video, when the compressor is held down with a release setting that is too long, there is a flatness or dullness to the sound and a whole bunch of other negative adjectives on this list. If you are using a compression take note if any of these bad adjectives start to creep into the sound.
- Too Thick
- No Dynamics
- Pumping (in a bad way)
Compressing A Mix or Group
The best was I’ve heard for listening to compression was described by mastering engineer Warren Sokol as “Listening to between sounds”
In his specific case he is talking about adding compression to an entire mix of a quieter genre of music. There are details that start to emerge with compression that are heard if you aren't focusing your listening on the main sound sources.
What does that mean for other music like EDM? Even if the difference in dynamic range isn’t huge, and there isn’t a lot of space between the loud parts, there are still beats that are hitting harder and then there is the sound between. Your compression on your entire mix is adjusting this relationship.
Listen to how the impact of the beats change and how well you can hear what is between them. You can also think in a similar way for individual instruments.
Compressing Individual Instruments
If you are compressing a snare for example, there is the initial loud hit(controlled by attack), and then there is a body to the snare (controlled by release). When listening to how your compressor is working on an individual element, try to focus on which aspects are being turned down and which ones are turned up.
For a snare you will be turning down the initial hit and turning up the the body. Zero in on how your compressor is changing that relationship rather than the tonal quality of the snare. If you turn the initial hit down too much, you might have a full bodied snare but it won’t have any impact.
Mixing is an abstract art form and compression is the most abstract tool in the bag. It takes time and practice to be able to get good at. Just remember to ask yourself, “Does it feel better or worse?“.