Advanced Production Technique: Sidechain Compression

One of the most common production techniques that I use in my work is the technique of Sidechain Compression. Sidechain compression has kind of become a big part to my sound as I tend to opt for very heavy use of it to allow my drums to pump through the mix. I've been learning more about different ways to apply it this trimester.

But what is Sidechain compression?

Sidechain compression is used in a range of musical genres, however it is very commonly found (especially in more extreme instances) throughout electronic music. Sidechaining as a term on it’s own is essentially described as: “any dynamics processor (for example, a gate, expander, compressor or limiter) uses two input signals: the incoming audio itself and a side‑chain, which feeds the detection circuitry that determines whether or not the processor acts on the material. Simple processors take their side‑chain signal directly from the audio input.” ("Q. What is side‑chaining, and what do you use it for? |", 2011)

This basically means that an external audio source is used to trigger the audio processer in which the sidechain mode is being used on. With sidechain compression this makes it so that the external audio is being sidechained to the gain reduction element of the compressor. A common example of this is used on radio where someone is speaking over background music, sidechain compression allows it so that the music in the background ‘ducks’ when the presenter is speaking so that they can be heard clearly - rather than fighting in volume over the top of the music. ("Sidechain Compression: Part 1 - Concepts and History", 2018)

An analogy of this could be for example we want to hear a kick drum punch through a mix each time it hits, instead of reducing the volume of the mix each time the kick comes through to allow space for it, we could instead use a sidechain compression technique to ‘gain reduct’ the mix each time the compressor is triggered by the external source.

("Q. What is side‑chaining, and what do you use it for? |", 2011)

Because it is taking the level of external audio into account, the louder the external audio, the more the sidechain reduces the audio. Sidechaining is often used in Electronic music to allow the drums to come through clearly in the mix over all the other processed elements. This is often used with the kick drum to allow it to pass through as it is what drives a lot of electronic music, but also because electronic kick drums often interfere with the sub and general low end of the mix.

This is used in my current projects as sidechain compression can be a great tool to help layer an 808 bass with a kick drum as the frequencies especially interfere with each other, create a clipping like effect and generally just don’t like to sit well together. A sidechain compressor with a short attack speed can however allow for the 808 to momentarily duck in volume when the kick is playing to combine the two sounds so they fit with one another. I have also used it as a corrective tool in my Electronic Indie Rock track to sidechain out some of the drum bleed, but i’ll be writing a full breakdown of this in my drum processing blog.

What I researched to improve my 808 and kick sidechain compression

("How to SideChain Your Kicks and 808s | MrDifferent", 2016)

An example of some rather harsh sidechaining can be heard in Purity Ring’s song Fineshrine which i’ve linked below.

("Purity Ring - Fineshrine", 2012)

If you listen closely to the kick in this song we can here that it’s very clear sounding as all of the other elements quickly duck in volume whenever the kick appears, making it sound prominent and gives it a pumping type effect.

That’s what sidechain compression is and how i’ve used it on my current projects. I’m interested to learn more unique ways to apply it in the future!

References

How to SideChain Your Kicks and 808s | MrDifferent. (2016). Retrieved from https://www.youtube.com/watch?v=PfemwkZzXmI

Purity Ring - Fineshrine. (2012). Retrieved from https://www.youtube.com/watch?v=Xqw4wo8vdY8

Q. What is side‑chaining, and what do you use it for? |. (2011). Retrieved from https://www.soundonsound.com/sound-advice/q-what-side-chaining-and-what-do-you-use-it

Sidechain Compression: Part 1 - Concepts and History. (2018). Retrieved from https://www.ableton.com/en/blog/sidechain-compression-part-1/