Sidechaining is this: taking a piece of one signal and using it to do something for another. Let's think of a few examples of what a sidechain can do.
1) A De-Esser. This is a compressor with a sidechain EQ. The sidechain EQ looks at the source and you can adjust which frequency to attenuate. The de-esser selecectively compresses ONLY the selected band(s), usually somewhere above 5khz, to remove the sibilance from some voices.
2) Realistic Reverb. You can trigger a reverbs using mulitple sidechain compressors, so that when your voice gets above oh let's say -25dBFS, your voice is sent to a Small Room Reverb. However, once your voice goes to -12dBFS, your voice is sent to a Large Room Reverb. Why is this realistic? When your are in a space, you can't really hear too much of the room partially because you are influenced by what you see, but also because of the actual loudness of a voice. When a singer sings loudly, however, the voice can travel all the way to the back of the room, allowing you to hear how big the space really is. You get this effect in small venues listening to singer-songwriters.
3) A Gate's "Listen" or "Key" function. What this does on a gate is only release the gate for signals of a given frequency range. This can help a lot when gating kick drums and toms because you can choose a lower frequency as a key input so that the snare drum (usually the loudest thing) doesn't trigger the gate. Just select your frequency range and the gate will stay quiet until something in that frequency range is hit above the threshold, but it will play back the full sound, not a filtered sound.
4) Kick / Bass Dynamics - This is the CLASSIC example of sidechaining that we're going to deal with today. This is where the kick triggers a compressor to turn down the bass guitar every time the kick hits. Why? Well the kick drum and the bass both share a similar frequency spectrum. Both have a wide response, from sub lows to present highs. The problem is, these instruments often compete if not played well. There's a certain "married" sound that you get from a bassist and drummer playing together in the groove. It's undeniable; it sounds like they are perfectly on and the bass is locked in with the kick drum. This can create a really punchy and tight sound and should REALLY be used when you're having trouble hearing both kick and bass fully. I've made two tutorials to explain how to do it!
You will need:
1. A compressor plug with a key input function. N4 has this, but N3 and C4 do not. See below.
2. The video tutorials that I made!
A free vst compressor plugin (to engage key in, turn up "KeyVolume" to 0.0dB):
Here are the videos for you to enjoy! Best Viewed Maximized and in HD.
NUENDO 3 / CUBASE / OTHERS