Add rhythmic interest to sustained sounds using the intriguingly named ‘Phantom Trigger Sidechain Technique"‘ Ufuk Onen explains how to add movement and interest with just the tools in your DAW and a little know-how.

What Is A Compressor Sidechain?

The ‘sidechain’ of a compressor refers to the signal controlling the compressor. A compressor is basically an automatic volume control which ‘listens’ to a signal and turns the volume down when that signal gets loud. Usually the signal being listened to is the same one as is being turned down. this is known as an internal side chain. When people talk about ‘sidechaining’ they usually be an an external side chain. In this case the compressor is listening to a different signal to the one being processed by the compressor. Hence ‘external side chain’.

‘Phantom’ Sidechain

This technique is a variation of extern al side chain conpression. Why is it called 'phantom trigger'? Usually, when we control a compressor inserted in a track via an external sidechain with a signal from another track (see the image above), we have both of these instruments, the controller/trigger and the controlled one, in the mix. That means we hear both the kick (trigger) and the bass (controlled track). 

In the phantom trigger technique, however, the controller/trigger track is absent in the mix. We don't hear it. Hence the term 'phantom trigger.' 

Below, I demonstrated this phantom trigger technique using Logic Pro, but you can apply it in any DAW.

First, I created a MIDI channel, inserted a stock pad preset that comes with Logic Pro (Classic Brass Pad), and recorded a few chords. Here's what it sounds like:

Let's add excitement, movement, and a sense of rhythm to it!

I created another instrument track and inserted Ultrabeat, Logic Pro's stock drum machine plug-in. Then I created a pattern region for it. You can use any pattern-based drum machine plug-in.  

I wrote a 4-bar pattern, named it "Phantom Trigger," and duplicated it to have a 16-bar trigger track. Below, you can listen to the pattern that I wrote. 

Here comes the critical part: As the next step, I inserted a compressor into the pad track. Then, I routed the output of the drum machine track to a bus that carries the signal to the sidechain input of the pad's compressor. So, the output of the drum machine goes into the sidechain of the pad's compressor, not to the main mix. The drum machine is now a 'phantom trigger.' It controls the pad's compressor but is not heard in the mix.

As you can hear below, the pad became much more interesting. It now has a feeling of movement and a sense of rhythm.

To check how it would sound with drums, I added a loop. Here's what it sounds like:

It is possible to create an infinite number of variations, not only by changing the pattern of the phantom trigger but also by experimenting with the attack and release times of the pad's compressor as well.

Give it a try!