After two important posts on EQs, it’s time to start discussing how to use compression, as these two work so well hand-in-hand, and I’ll offer my own recommendations on some of the best compression VST plugins. Your own selection of VSTs should always start with a few of these two categories:
- One Parametric EQ for surgical needs.
- One Shelving EQ for toning.
- One analog based EQ for coloring.
For compression, there are also several choices and it’s easy to get lost, so one of the things I find important to start with is to explain the different families of compressors (more suitable to relate them to as models).
This type of compressor is one of the most popular out there. It’s known for its aggression and for its use of adding tons of punch to sounds, mixes, with a lot of attitude. The FET compressor, which means Field Effect Transistor, appeared later in the history of compressors, when they switched the tubes for to a model that helped make sounds warmer and richer; it became an instant favorite in studios. The 1176 is one compressor that became one of the most popular models in studios.
Use: Amazing punch on percussion and add life on textures, pads.
Black Limiting 76 (IkMultimedia)
This type is pretty much the opposite of the FET (although there are people who will argue about this). The Opto model is smooth and super warm. Not idea for percussion but I do use it in parallel (see techniques below), which can give beef to a kick, for instance. The way this model works is very interesting. It’s basically a lamp that reacts to the incoming sound and will light up depending of the incoming signal. I’m not the best at explaining this, but that pretty much sums it up, and this makes the Opto compressor not the most aggressive, as it offers smoothness.
Use: Ideal for pads, synths, textures and I would recommend you experiment it with percussion, but in parallel mode.
Notable suggestions for VST:
Renaissance Compressor by Waves also offers an Opto mode.
VariMu is like the prince of compressors because it has finesse and elegance. Manley popularized the VariMu with their famous version of it. It is a cousin of the Opto in the way it works, and is also very smooth. Often used in mastering, it works like a charm to handle punch problems or to keep coherence in a mix that needs general glue to it. It’s not the best to create punch and this is why, but when used in pair with another compressor, it can really create beautiful results.
Use: On your mix or on a group. It will glue it all together in the most luscious way.
Suggestions of plugins:
This type of compressor is also very popular just like the FET. I’d say that most generic compressors are often based on that model. Since it’s based on voltage control, this compressor is a surgical type of tool. It is really effective to produce snappiness to percussion but it can also be used to control harsh transients.
Use: Smack those kicks with it and control the transients of hats with another setting.
You may have the best plugins but if you don’t know how to use them, you’ll miss the full potential of these amazing tools. I’d say that if you don’t, please know that a large number of producers out there, even experienced ones, struggle to fully understand them. So while you will find so many tutorials out there, I’d like to explain you my simple vision.
But first, let me explain what compression does. It takes the incoming sound and monitors the loudest peak and checks if it is louder than a certain point: the threshold. If that’s the case, it will push down the signal above the threshold, down. I like to picture it as when you sit in a bath, where the water rise as you sit in it. The way a compressor “pushes down” the audio will be controlled by the attack (how fast it reacts), release (for how long) and ratio (how much).
I’d like to compare a compressor to an oven and the incoming music as the dough. The compressor doesn’t work like, let’s say a reverb where if you put it on a sound, you’ll automatically hear what’s being altered. How compressor VSTs work are really, to me, like a oven. You need to bring in the sound, cook it, then push it out.
So, use these parameters when dealing with compression:
- Incoming signal. You’ll need to raise the volume of the incoming signal to make sure it meets or is above the threshold. If the signal is too low, it won’t be processed.
- Threshold. Lower it down if needed. You’ll see that most compressors have a “GR” for gain reduction meter. This will start to pump as the signal meets the threshold. If nothing happens, lower down the threshold and or boost the incoming signal.
- Attack/release. A fast attack will make the pumping start react quickly while a slow one will be less aggressive. You can then adjust the release to control for how long the pumping will last.
- Ratio. This is how much will be pushed down. For instance, a 2:1 ratio means that for 2dB over the threshold, it will be turned down by 1dB over the threshold. Eg. 8:1 is a more aggressive result.
- Make-up gain/Output. Your output signal will be turned down in the process so you can use the make-up gain to adjust the processed signal to match or be louder than the incoming signal.
So yeah, it sounds weird on paper, but compression is about lowering the volume to make things louder.
Regarding my analogy with the bread, you need to make sure it bakes (gets compressed) before pushing it out.
Now, the techniques you can use compression for:
- Limiting. This is the most known use of a compressor. It is a way of making sure the sound never goes above a certain level. Ideal on a master bus to avoid clipping. You can use it to a certain extent on busses to maximize the volume. But make sure it’s not too much as it can then distort in mastering.
- Side-chain, ducking. Popular in electronic music, this makes the compression work based on an incoming signal. I’ll get back to this in a future post.
- Parallel compression. To do this, you need to put the compression in an AUX/Send bus and then send whatever needs compression to it. This ensure the original signal is mixed with the compressed one, adding power, loudness, precision.
- Serial compression. To be used with care, but has very powerful results. This is about putting two (or more) compressors back to back. One can be in parallel (thanks to a wet/dry) and the second one, not. This makes sounds really powerful, punchy, fat. Ideal on sounds that are wimpy and pale.
That’s it for the basics of compression! I’ll discuss the art of sound design using compression and EQs next.