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Sidechaining and Ducking in Reason

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Read Time: 4 min

Side-chaining and ducking is certainly a popular topic amongst today's production fraternity. Mainly used to create pumping effects in electronic music, the process still remains a mystery to a lot of people. Things can become especially confusing when a program has its own tools for the job. Mo Volans gives you a Reason to duck...

Note: this article contains embedded audio that will not display in a feed reader. Click back to the site to read the tutorial with audio, or download the audio files at the bottom of the post.

Step 1

First up, identify the sound you want to treat with the side-chaining process. This can be anything really, from a synth pattern or vocal hook to a percussion pattern or loop. Basically, this is the sound you want to be affected and to change in volume, so if you are looking to create a pumping bass-line your bass sound would be inserted at this point.

To keep things simple I’ve used a Rex loop from the Reason sound library. I have chosen a musical phrase/loop that will react well to the side-chaining process.


Step 2

Next, patch your ‘target’ sound to its own channel on a a reMIX mixer. This will not only give you control over the sound's level and pan controls but will also give you basic EQ controls if you need them.

Step 3

Insert an M Class compressor inline with your target sound device. Do this by right-clicking or control clicking on the device.

When you've done this you'll notice that Reason automatically routes the new compressor and essentially creates an insert effect set up. Your control over the sound using the channel on the mixer will remain the same during this process.

Step 4

This is as good a time as any to commit the part you are using to its own midi track. Of course, you may already have this set up if your part was constructed using Midi originally.

If you are using a loop--as I am in this example--you can right-click on the device and go to “copy REX loop to track”. This will convert the loop's playback to a midi part and will save you having to hit preview every time you want to hear it (and of course you can edit the result as well!).

Whilst in the sequencer viewing your new midi part, it's a good idea to set a loop up so you can audition your new part continuously. Do this by using the locaters and the loop on/off function on the right of the transport.

Step 5

Now it's time to choose your trigger or ‘key’ sound (a compressor side-chain input is sometimes called a key input). Again, this can be anything, but in this instance I’ve used a 4/4 kick drum from a Redrum drum machine. We’ll use this sound to trigger the ducking process and create a classic pumping effect that's so popular in electronic music.


Step 6

When routing your trigger sound to the compressor's side-chain inputs you have to ensure that you can still hear the sound in your mix. Simply routing the main outputs of your trigger device will result in the sound disappearing from you mix.

One good way around this issue is to use auxiliary sends. To do this, connect one of the aux sends to the side-chain inputs of the compressor and send a healthy amount of signal from the trigger sounds channel on the reMIX mixer.

Step 7

Once you have your side-chain compressor working correctly you can start to perfect its settings. Using fast attack times will make it react quickly to your trigger sound. The release has to be set so that it breathes with your music. Some experimentation will help here.

High threshold and ratio settings will give you extreme pumping effects if that's what you're after. For more subtle and transparent results go a little easier on the settings.

Step 8

Use the mixer to balance all the levels so that they work together and continuously tweak the compressor's settings and amount of input level going into the side-chain compressor. Using this process you should be able to create a comfortable marriage of the two elements.


Step 9

When you are happy with your overall balance you can add extra elements and processors to the mix. Try adding delays or reverbs to the side-chained sound before the compressor: this will mean any processing added will also be ducked, keeping your mix in line.

Additionally, a limiter after the compressor can control any wayward dynamics introduced by the side-chain process, although go easy here or you’ll iron out the effect completely!

Listen to an example of this technique in action:


Download the Play Pack for this tutorial (4.4MB)


  • Printable PDF Tutorial
  • Mo's Reason source file
  • Audio files

Hear examples of Mo's work or drop him a line at or

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