Compression reduces the dynamic range of an audio signal, squashing the low and high volume parts, closer together. Sidechain compression does this, following an input signal.
You can sidechain compress things like the bass out of the way of a Kick drum for instance. Every time that Kick drum hits, the bass channel will duck, creating space and a cool pumping effect.
In this article we’re going to show you how to sidechain in Ableton, using the compressor. You can use the glue compressor, or any other 3rd party compressor plugin – the steps are identical.
1. Load Ableton's Compressor On A Track
First, you need to load your compressor on an audio signal that you want to be ducked out of the way of your sidechain signal.
For instance, if you want Bass to duck out of the way of a Kick, you put the sidechain compressor on the Bass channel, and use the sidechain input as your Kick.
If you want your chords to have a pumping rhythmic effect to the Kick, put the compressor on your chords, and the sidechain input as your Kick drum.
2. Enable The Sidechain Button
To enable the sidechain button, you’ll need to click the down arrow, top left of Ableton’s compressor. It looks like this:
Once you’ve clicked the arrow button, you’ll see a new menu open on the left. Here you have sidechain compression options.
Then you need to enable the sidechain toggle button on the left, so it turns yellow, as you can see from the image below.
3. Choose Your Sidechain Input
Next, you need to select your sidechain trigger signal. Just below the sidechain button, under “Audio From”, there’s a drop-down menu that will say “No Input”. Here you can choose from an audio signal or MIDI track. You can also choose busses too.
In this case, you’ll want to choose your Kick track, because this is what you want as your input to use as the sidechain signal to duck your Bass out of the way. For us this is: “MXC 123 Drums Kicks 12”.
You can also choose from a Drum Rack if that’s how you do your drums. In this case, you’d see this come up as an option on your sidechain input menu.
It would open up to show all your Drum Rack tracks, here you’d just choose your Kick Drum Rack track.
Below the sidechain input there are 3 options:
- Pre-FX – before any signal processing is applied to your sidechain input source.
- Post- FX – after an FX like EQ/Compression/Saturation is applied. This is usually the best setting.
- Post Mixer – allows you to turn down the sidechain input, as you turn down the level of your track.
Most of the time you’ll want to use Post-FX because this will use the signal after all of the processing has applied. However, there are cases where Pre-FX might fit the sound better. Post-FX also allows you to change the volume of your tracks, without affecting the level of your sidechain trigger signal.
4. Choose Your Sidechain EQ
Next to the sidechain button, you can select the headphone & EQ button.
This will allow you to sculpt your sidechain input before it goes into the compression phase of the process. The headphone button allows you to listen to the EQ’d/filtered signal that is going into the compressor.
You can choose from a number of filters, but the most likely one you’ll use when sidechaining the Bass to the Kick, is the low pass filter, or the low shelf. Using this you can remove some of the Bass from your sidechain input signal, which can be useful when you don’t want the sidechain compression to overload, and last too long.
Specifically Bass can be a tricky frequency, and due to its loudness, it can cause the compression to squash your signal longer than it needs to be.
If you filter out your lower-end bass, up to 100-200Hz, this leaves the body of the Kick and gives a more clean, precise sidechain compression.
Sometimes you may want this longer, heavy effect that’s not as precise. Especially in EDM when you want the sidechain to be heavy, it’s useful to leave much of the low end in, so you can get that long pump effect you want.
Some tutorials online say that the EQ can affect where the frequency range of your sidechain is ducked, however, this isn’t true. The compression will duck the entire signal no matter what. Filtering just gives you a slightly altered input that may change the speed and precision of your sidechain compression.
If you want to duck a certain frequency range, you can add multiband sidechain compression, which we’ll explain further down (really useful for sub heavy sidechain Bass compression).
5. Set The Threshold, Attack & Release
Next, you’ll want to start changing the threshold, attack & release settings on your compressor.
First, change the threshold of your compressor.
The threshold will set the db level at which your compressor will begin to react. Without a threshold level, you won’t hear any compression, so you need to set this first.
After this change the attack settings.
Depending on your signal, you might have different settings here. Because we have a Kick, we want a quick attack, so that the compression ducks our Bass quickly out of the way.
When changing the attack you might also notice a clicking sound. If your attack is low (like 1ms), you’ll get this clicking noise. To stop this from occurring, you need to push your attack up a slight bit more.
After setting the attack, you'll set the release.
The release controls how quickly your compression stops. You want to dial in your release so that it recovers before the next Kick hit, and allows your compression to hit again from the 0 point. Your release settings will depend entirely on how you’d like your sidechain to react.
Most of the time you’ll want a fairly quick release of something like 50-200ms, especially when sidechaining to a short Kick.
Aggressive Pumping Sidechain Effect
If you’re looking for the creative, EDM, rhythmic sidechain effect it’s pretty easy to do, and you can do it in your music production sessions, with the stock Ableton compression plugins.
You may have seen some music producers use enveloping tools to do this, and these essentially do the same thing as compression, but give a little bit more control over the shape of the sound.
If you want to apply an aggressive sidechain using the Ableton compressor, first set the ratio to anywhere between 4:1 – inf:1. For heavy sidechain compression, we prefer using inf:1, which is the highest setting you can get.
Then you’ll want to set the threshold so you have 8-10db gain reduction.
For the attack and release, this really depends on the tempo in your music production project, and you need to work this out using a formula when going for the dance style pump effect.
As you can see from the above image, if you wanted a 1/4 note syncopation on your sidechain, you’d need to use 500ms on your release. This would create that classic breathing effect, that’s so common in EDM.
Multiband Sidechain Compression
As we mentioned above, sometimes you might want to duck certain problem frequencies out of the way of a particular element. This is useful in the case of Sub Bass and Kick clashing frequencies, especially in dance music & EDM.
To set up the Multiband sidechain, you can use Ableton’s audio effect rack and the multi-band dynamics plugin.
1. Open An Audio Effect Rack & Multiband Compressor
On the audio signal, you’d like to duck out of the way of your Kick, open up an audio effect rack, and drag a Multi-band Dynamics plugin in.
2. Create 3 Audio Effect Rack Chains
In the audio effect rack, you notice a 3 line button, click this and it will open up a new part of the audio effect rack.
Then you’ll want to highlight the chain you have and hit “Cmd d”, or “Cntrl d”.
Name these chains:
3. Separate Low, Mid & High
After you have your chains you want to separate them into 3 frequency ranges. Because you have your multi-band dynamics compressor, you can solo each of these ranges.
So, on the low chain, you want to solo the low section on the multiband dynamics compressor and do the same for the mid & high.
4. Select Frequency Range Compression
Next, you need to open up a compressor, on the frequency range that you would like to duck out of the way. In the case of the Kick & Sub Bass, you’d want to duck the low.
To do this, open up a compressor on the low chain of your audio effect rack, after the mulitband dynamics that you have set up.
5. Apply Sidechain Compression
To sidechain you Bass to your Kick, you want to follow the steps above that guide you through the sidechain compression process.
Using Autopan For Easy Sidechain Effect
idechain works by ducking a signal out of the way of another. This is especially useful in a mixing scenario, but can take a while to setup if you only want the creative, rhythmic, or pumping effect. In this case it’s much easier to use volume automation tools.
In Ableton, you can use the Autopan plugin to create this volume ducking effect extremely easily.
It’s something we personally always use for sidechain, pumping reverb effects, and other rhythmic patterns, that we want to apply quickly.
This gives you far less control and is more of a creative effect.
To do this, open up an Autopan on the track that you want to volume duck. Then, you need to change the phase to 0 degrees. This stops the panning effect from being applied to your audio signal, and now works as volume automation.
You can then select a beat division you want your autopan to affect the volume of you track, and push the amount up, then you will start to hear the volume pump in time with the beat division you have selected.
If you're looking for a quick, sidechain like effect, the best shape to choose is the saw wave shape.
This creates an envelope that has a short attack, and short release, which is exactly what you want when you’re sidechaining something. After this, you can change the shape of this which gives a longer attack and shorter release.
How To Sidechain in Ableton: Summary
Learning how to sidechain in Ableton is easy. In this article we've covered how to sidechain in Ableton in 5 easy steps, without the need for a sidechain capable VST, just using the stock compressor.
By now, you should be able to use the normal Ableton compressor to sidechain. The process is the exact same for the glue compressoThis creates an envelope that has a short attack, and short release, which is exactly what you want when you’re sidechaining something. After this, you can change the shape of this which gives a longer attack and shorter release.
You just press the sidechain button, select the right track for the sidechain input track.