Sidechaining, or ducking as many may refer to it, is one of the many different types of musical compression. As with other types of compression, sidechaining employs the principle of throwing away one piece of data to accentuate another.
Sidechain compression is most often used today in dance and electro house music. They are not the only genres to implement the technique, but they are two of the most common.
When first beginning to produce electro house and dance music myself, I received moderate amounts of positive feedback about my music. But I just wasn't achieving that professional sound, and a few people were honest enough to tell me this. So I began to listen to more electro house music, and I don't mean just listening for mere pleasure. I listened to the music carefully, asking myself how certain sounds could've been made; or what effects could possibly have been used to make the instruments sound the way they do.
This is when my ear began to pick up on the pumping sensation that seemed to occur in almost all of the songs I was listening to. In certain songs, the baseline seemed to pump, giving the song life and making it sound punchier. It almost sounded as though the kick drum was imposing on the baseline to make it pump, or dip in volume.
I later learned that the pumping sensation was called Sidechain compression.
Sidechaining basically takes one sound and uses it to manipulate another. Most often, this manipulation occurs between a kick drum and the baseline, with the kick drum usually doing the manipulating. For example: the baseline will duck in sound every time the kick plays, to create that pumping sensation.
Here is a simple demonstration of ducking/sidechaining that I created.
Hear how every time the kick drum hits, the baseline ducks. This is sidechaining. Also notice how the first six seconds sounds flat, untidy, and a little bit too loud. The last six seconds sounds more professional and commercial.
Here is a more obscure example of sidechaining that I created.
The exact same thing is happening here as with the example earlier, except this time it is the bell instrument being ducked/sidechained. The first fourteen seconds, there is absolutely no ducking taking place. However, within the second half of the example, the kick begins to impose on the bells. Hear that pumping sensation?
When people usually refer to sidechaining or ducking, they are usually referring to hardware sidechain compressors, or software sidechain compressors, which you can use to integrate ducking into your music.
Sidechain compression is an essential mixing skill for dance music, electro house, and many other genres, helping to make your music sound a lot more commercial and professional.
