WHAT IS COMPRESSION?
One of the most used, misused and most misunderstood tools you’ll run across in the recording process is compression. So what do YOU need to know as an artist new to the studio environment?
A “compressor” is a tool – either a physical piece of hardware or a software plug-in – used in recording and mixing music.
At the core, compression is simply minimizing the difference between the loudest and most quiet parts of a sound (the dynamic range).
This is done by either reducing the volume of a sound every time it reaches a certain point (downward compression) or increasing the volume of a sound every time it falls below a certain point (upward compression).
There are many adjustments that can be made including how quickly a compressor reacts to a sound (attack), how long before it stops reacting (release), what volume needs to be reached before the compressor kicks in (threshold), and the degree of compression applied (ratio). There are also many different types of compressors that react to the sound in different ways.
BUT let’s look at the practical application of compression because I assume this is what you really care about.
The most common uses for compression you’re going to be concerned with are:
1. To evens things out. On your lead vocal or other lead instruments, compression will keep it up front essentially by keeping it at a fairly consistent level. On the entire mix, compression will give a smoother and louder over-all sound.
2. To either soften or harden a sound. This is especially noticeable on percussive instruments like drums, acoustic guitar, or piano. A compressor can give the sound a soft “squishy” feel or a tight “snappy” feel – mainly by adjusting the time it takes for the compressor to attack.
3. Similarly, a compressor can extend or cut short a sound. This is especially noticeable on a lead guitar – if you want to make that note last forever (sustain), a compressor can help. If you want it to end abruptly, a compressor can help with this too. On drums, it can make the difference between a very tight staccato sound or a huge, squashed and sustained sound.
This really just scratches the surface of what a compressor can do. Every engineer has his/her own little tricks. There are multi-band compressors that will compress different frequencies (bass – mids – highs) in different ways. A type of compression is used to minimize sibilance (the “esss” sound) or plosives (the “puh” sound). You can even apply the compression from one instrument (like a kick drum) to another (like a bass guitar) so that the two sounds don’t compete (this is called “side-chaining”). For a little more in-depth explanation, visit Wikipedia’s article on dynamic compression.
With a general understanding of what a compressor does, you should have more control over your sound and an easier recording process. If you’d like more information or have any questions or comments about any part of the production process, feel free to contact me at firstname.lastname@example.org.
Jonah Brockman is an independent music producer and engineer dedicated to empowering songwriters with the resources they need to make great music. Visit jonahbrockman.com for more information, rates, and work examples.