What is Audio Ducking and How to Do It in Music Production
Learn what audio ducking is in music and dialogue editing, and how to use it to add clarity and presence in your productions.
Audio ducking is a highly useful mixing technique you can use to improve the clarity of elements in a mix. It’s arguably one of the best skills to have in your mixing repertoire, but what exactly is audio ducking? In this article, discover what audio ducking it is and when to use it in your mixes. Then, I’ll show you how to do audio ducking using
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What is audio ducking?
Audio ducking is simply the process of compressing (or “ducking down”) the volume of an audio signal whenever another audio signal goes above a certain threshold. When used gently, this technique allows you to get more clarity from both audio signals. And, when used at a more extreme level, audio ducking can help create some interesting sonic flavors to give an instrument (or an entire track) a really unique vibe. A popular method of audio ducking is sidechain compression, shown below with Neutron Pro.
Although largely popularized by EDM genres like French House (the pumping vibe of Daft Punk’s “One More Time” is achieved by using sidechain compression), audio ducking has been around for a very long time. You can even hear this technique being used on the cymbals in The Beatles’ classic track, “Tomorrow Never Knows.” Whenever the kick drum hits, the cymbals duck down in volume to ensure the two percussive elements aren’t competing too much for attention.
Now that you know what it is, let’s go over some typical ways audio ducking is used in music production so you can start finding scenarios in your own mixes where you can apply this concept.
When to use audio ducking
Audio ducking can be a very versatile effect and will yield different results depending on the two audio signals being used. And, whereas there are some tried and true instrument pairings that respond very well to audio ducking, you can use this compression trick anywhere you’re looking for more clarity from two instruments that are clashing in a mix.
Audio ducking in music
One of the most common uses of audio ducking is for dialing in the relationship of the kick drum and the bass instrument in a mix (I’ll be getting into this scenario in more detail down below). But, like in The Beatles example above, you can also apply sidechain compression to percussive elements in a mix in order to draw attention, emphasize the cadence, or just save more mix headroom in your percussion section. Since you’re compressing the volume of one element when another one is present, you can achieve mixes that are perceived louder—not just clearer.
One of my personal favorite ways to use audio ducking is on a vocal’s reverb. When you apply audio ducking to a vocal’s reverb bus (sidechaining it to the dry vocal), it allows the vocal to punch through without getting washed out by the reverb. iZotope’s Exponential Audio reverbs include this reverb ducking with ‘tail suppression’ and ‘tail recovery’ features. Any time the dry vocal is present, it will cause the reverb to duck down in volume. But, between words and phrases—when the vocal isn’t triggering the audio ducking—that reverb is able to swell up in volume, giving the listener the illusion that it was there the whole time. This use of audio ducking is especially useful on ballad vocals with very long-tail reverbs. Check it out in the audio examples below.
Vocals Before & After Audio Ducking
Before applying audio ducking, the luscious reverb on the vocal tends to drown out the phrase and muddy things up. But, can you notice how much more clear the vocal sounds after using audio ducking on the reverb bus? By using this compression trick, you can get a vocal that’s present, while still retaining that huge, larger-than-life feel.
Audio ducking in podcasting and post production
People mixing podcast vocals or spoken dialogue with background audio can also use this concept to enhance the clarity of a vocal. Similar to the vocal reverb example above, audio ducking allows you to make sure the background music or audio signal is still present, but not interfering with any vocals’ intelligibility.
So, when should you use audio ducking in your productions? Really, anytime you need an element in your mix to stand out and not conflict too much with another element. When used properly, audio ducking effectively allows both elements their time to shine.
How to use audio ducking
Now that I’ve explained the concept of audio ducking, let’s look at how you can achieve this effect using Neutron Pro. For this example, I’ll be sidechaining a bass instrument created with Native Instruments’ Massive X to a four-on-the-floor kick drum loop (this is the trick for getting that classic “pumping effect” common in much of the EDM we hear today).
Here's the before and after with audio ducking in Neutron Pro:
Audio Before & After Ducking in Neutron
In order to set up audio ducking, you first need to add an instance of Neutron Pro to your bass track and set the sidechain input to receive audio signal from your kick track. How to do this step will vary based on which DAW you’re using, but a simple Internet search for “how to set up a sidechain in (insert your DAW here)” should get you rolling in the right direction. iZotope shares how to do it in Logic below.
Then, towards the top of Neutron Pro’s plug-in window, add one of the Compressor Modules. In the main window of the Compressor module, turn on Sidechain to Ext Full. That’s all, folks! Now, you’re all set up to start audio ducking in style.
From here, you can drag the Threshold slider down until it’s compressing your bass to your liking. And, feel free to play around with the Attack, Release, and Ratio controls to dial in the exact sound and amount of “pump” you’re going for.
And, here is a screenshot of how I set the parameters for this example:
One last note: in Neutron Pro, there’s a handy, new Oscilloscope view that helps give you a good understanding of how your signal is being processed by the audio ducking (to activate the Oscilloscope view, simply click the sine wave icon towards the top left of the Compressor module’s window). In the screenshot above, my bass audio appears in white and the sidechain signal from my kick track shows up in purple. This is an incredibly useful tool to allow you to see what is actually happening to your waveforms as you make adjustments to the various controls in the Compressor module.
If you want to learn more about how to use Neutron Pro’s Oscilloscope view for audio ducking, check out the video below.
Start using audio ducking in your productions
Audio ducking can have so many different applications in mixing, so it’s definitely worth trying out this concept in various ways in your own mixes. Whether you’re needing more clarity from competing mix elements, or you’re just trying to create an interesting vibe, audio ducking can be a useful skill to master. Plus, with how easy Neutron Pro makes it to set up audio ducking, it’s a no-brainer.
If you don’t already have Neutron Pro, you can get full access to it (and start trying out audio ducking for yourself) by signing up for a
iZotope Music Production Suite Pro: Monthly