When I first started learning about mixing, the most challenging aspect for me was learning how to apply compression. I just couldn’t wrap my head around it. When I would ask senior engineers about compressors they would give some really abstract examples that would go over my head. I thought I was too stupid to get it. I promised myself if I ever figured out how compressors worked I would teach it one day in a way that someone as dumb as me would get.
Compression is the most challenging part of mixing, but it is also the most rewarding. It’s what separates a pro sounding mix from a “home studio” mix. Applying compression to various tracks in your mix will help you achieve that nice even sound. Okay enough about why it is important, let’s break down what each knob does.
The ratio knob determines how much compression to apply. If you apply 2:1 ratio, the sound will have very little compression whereas if you apply a 10:1 ratio it will have a lot of compression.
I’m not going to bother explaining ratios or how fractions work because your eyes will probably glaze over. The important thing here is to train your ears to hear what compression sounds like. Considering you’ve listened to music your whole life, you probably sub-consciously know what compression sounds like.
The key here is to train your ears to get used to what compression sounds like on your tracks. Treat it like a video game for your ears. You want to train your ears to hear what different ratios sound like on your drums, on your vocals, on your guitars, on your synths, on your brass section, etc. This is where tons of practice and experience come in and why top mix engineers get paid the big bucks.
When your vocals sound really squashed, it is because they have too much compression and when they sound too dynamic that is because they have very little compression.
Where finding the right ratio is about finding the right balance between a dynamic and squashed sound, setting the attack time is all about having a short or long sound.
For example, setting a short attack time on a kick will produce a very short sound that will sound like a “tock” or a knock. It is because the attack time is only allowing just little bit of that kick’s sound wav to be heard.
On the flip side, if a longer attack time is set then more of the thump of the kick will be heard, which you may or may not want
Try layering a kick with a short attack time with an 808 bass for to create a kick that is both well defined and has that low end boom.
Similar to attack time, release time tells your compressor when to “jump”. If you set a short release time, you’ll notice your track sounds very “jumpy” like it’s bringing up the quieter parts of a sound wav faster than it should be. For most cases, this isn’t the sound your looking for so you’ll want to set a longer release time. But if it does make the desired sound than by all means keep it.
Imagine a sound wav sitting in your living room the size of you. The threshold would be like a slider going from your ceiling to your floor and depending on where you set it, would determine how much of your wav gets fed into the compressor.
If you only want a little bit of your sound to have compression you would set the threshold at say -3 or higher. But if you want your whole sound to be compressed you’d set it at say -20 or lower. What you set it at really depends on your sound and the effect you are trying to achieve.
When setting the release time when mastering a song, aim for a longer release time to avoid that “jumpy” sound.
This is where the magic happens. Think of gain reduction like an intensity slider. When you move down on your slider that is increase the gain reduction, the effect is much more and when you move up on the slider that is lower the gain reduction, the effect is much less.
The effect of what you ask? The effect of your ratio, attack time, and threshold settings. Basically, your gain reductions job is to increase or decrease the intensity of the effect of your compression settings. At first you will hear it as a change in volume but with practice and consciously training your ears you’ll be able to hear attack time, ratio and threshold.
Is That All?
This is just a very basic tutorial on compression but should get you more familiar with how to use any compressors especially the more basic VST ones. Keep in mind, there are no correct setting for any of your compressor’s functions, it is all about achieving the sound you want to achieve.
Remember different compressors impose a different character on your sound, which really makes using a compressor just another artistic tool in your arsenal.