Using a compressor in your mix can be confusing at first. When I first started mixing I spent so much time trying to understand how to use compression the right way. It took me years to truly understand the correct way to use it on all my instruments in my songs. I decided to make it easy and break it down for beginners hoping to save someone from the headaches I went through when I started mixing. I even made a video that will show you visually what a compressor is doing to your tracks. But first, lets get to the basics of how a compressor works...
An audio compressor is used for lowering the volume of the loudest notes of an instrument while raising the volume of the quieter notes. Think of it as taking a ball of play duh in your hands and squashing it flat. That is exactly what a compressor does to an audio signal! We are simply squashing the audio signal of an instrument to make it quieter, and then adding overall volume back at the end to make the instrument more powerful.
When we hear are favorite songs on the radio we are hearing music the has been extremely compressed. And that is pleasing to our ears. What if you were listening to a song and the guitar solo had notes that were too loud? and what if in that same guitar solo there were notes that were much too quiet!? This would not sound good to our ears. Audio compressors help us avoid this by evening out the notes that are played by instruments and they are one of the most important components of a mix
If we want to understand how to correctly use a compressor in our mix, we first have to understand all of its controls and "knobs". A typical compressor using has these main controls....
The threshold determines what db level and audio signal must go over before the compressor actually starts to compress the signal.
If the threshold is set at -10db, once the audio signal gets louder than -10db, the compressor will start to lower the volume of the instrument.
The ratio determines how much the audio signal will be compressed after it goes over the threshold.
If you set your ratio at 2:1, and the signal goes over the threshold by 2db, the signal will be turned down to 1 db over the threshold. If your ratio is set at 2:1 and the audio signal goes over the threshold by 8db, it will be turned down to 4 db over the threshold.
Attack determines how quickly or slowly the compressor reacts to the signal that goes over the threshold.
For instruments like drums where we want to let the transient through and retain more "punch" we want a slower attack. For other tracks such as bass guitar or vocals where we don't want anything peaking out, we want a fast or medium attack.
Release determines how quickly the compressor stops compressing after the audio signal goes below the threshold.
If we want to bring an instrument more the the forefront we want the compressor to turn of fast. If we want an instrument more in the background we can accomplish this by using a slower release time.
Makeup gain allows us to add more volume back to the instrument after the signal has been compressed.
After turning down the volume of the instrument with compression a makeup gain knob makes it easy for the signal to be put back to its original volume.
Below are some of my go-to starting points for my attack and release time when it comes to specific instruments. This is the part that I had trouble with when I first started.....
Drums (kick/snare/toms) - Slow Attack/Fast Release
Bass Guitar - Medium Attack/Fast Release
Guitar - Medium Attack/Medium Release
Vocals - Medium Attack/Fast Release
If using a compressor in your mix is still a struggle check out this video I made where I show you visually what a compressor is doing to your tracks!
This guide will help take your mixes to the next level with your go to starting points for EQ and compression for all of your tracks. Just enter your name and e-mail and your guide will be e-mailed to you!