Up to Ableton Live version 6, the software didn’t include a compressor device with side chain input. Ableton Live 7 onwards introduced the new side chain enabled native compressor. The resulting effect is also called "ducking" and in this two-part tutorial we are going to explore it’s uses and demonstrate how his method can assist and enhance your mixing experience.

We are also going to look on how to apply side chain compression to multiple signals and also how to modify the spectral characteristics of the compressed signal so that only a certain frequency range can be affected. Finally we are going to spectrally modify a "busy" input signal so that only a certain frequency range will have an effect on our compressed signal. The Ableton Live version being used is 8.0.9.

Step 1: Setting Up

We are going to create the classic ducking effect using the sidechain feature from Ableton Live’s native compressor device. What we mean by that is that we are going to compress a signal according to another input signal that we are going to define in our project. I’ve prepared an electro style loop using a Drum Rack for drums, a percussion loop that resides in another audio channel, a bounced audio synth bass loop, and a white noise effect. (See the source files included.)

Listen to the loop:

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Step 2: Inserting the Compressor

Insert a Compressor device on the Bass track. Activate the External Sidechain button on the compressor. From the Audio From drop-down box, select Drums(our Drums channel) and from the drop-down box underneath, select Drum Rack | Kick | Pre FX. This way we command the compressor to activate itself only when the kick drum is heard before any effects are applied to the kick drum(we have no effects applied to it). Now, we need to set the compressor settings properly.

Here are my settings:

• Gain: 8.00dB
• Dry/Wet: 100%
• Envelope: Opto
• Attack: 0.01ms
• Release: 60.0ms
• Threshold: -25.0dB
• Ratio: 6.00
• Knee: 5.0dB
• Model: FF2
• Lookahead: 1ms
• Output: 0.00dB

Our intention is to cut the bass volume a bit but not silence the signal completely achieving a pumping effect. Experiment with the other settings depended on your source material. The small headphone icon at the right of the External Sidechain button is the Sidechain Listen switch. The switch disables the compressor’s output and allows you to hear only the sidechain input. This is a temporary diagnostic tool that can make it easier to set the sidechain parameters. You can activate it to mute the bass sound and listen to just the kick drum, our sidechain input.

The EQ settings allow you to modify the spectral characteristics of you input signal to allow certain frequencies from it to affect the target signal. It’s useful when we deal with a "busy" drum loop that contains both kick drum hi hats, snares, etc. We’ll get back to it later on.

Let’s listen how the kick drum affects our bass sound now

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Step 3: Ducking Multiple Signals

Currently our kick drum acts as the input signal compressing the bass sound. We’re going to use the same input signal to compress the white noise sample that gets introduced at the beginning of the 5th bar

So, listen to the uncompressed white noise sound along with the loop.

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For that we shall follow a different approach. Drag and drop the sidechain compressor to a Return channel. I put mine in Return B since Return A is already occupied by a Reverb. Group the device in an Audio Effects Rack by CTRL(CMD)+G or by select Edit->Group. An Audio Effect Rack is created with our current device located in the first chain. Show the Chain List and rename the Chain to Sidechain(CTRL(CMD)+R to rename). Right click underneath the Chain and choose Create Chain. Drop a Utility plug in and choose the Invert preset from Live’s Device Browser. Rename the Chain to Invert and optionally drag it above the Compression chain. That’s it.

Now increase the corresponding Send value for each track that you want compressed(currently the Bass and the White Noise) by turning the knob to the right. The more you increase each track’s contribution to the corresponding return track’s input the more compressed the signal will be as the Utility plug in in the Rack cancels out the signal coming from each track through its Send knob leaving only the compressed signal to pass through. This way we could have multiple tracks being compressed by the same input signal in various degrees.

Listen on how both the Bass and White noise tracks are compressed.

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That’s all for now. In Part 2 we are going to examine ways of ducking a frequency range using multiband dynamics and EQ and finally how to duck a “busy signal”. Thanks for your time!