I struggled with finding out how to get Side Chain compression with FabFilter Pro-C2 in Reaper – So, I’m making this guide in the hope that someone looking for the same thing – finds this simple example.

In this example, I want to compress, or “duck” some synths, to retain more consistent loudness in the Drums.

  1. I add all Drums to a Folder, and all of the Instruments that need Ducking into another Folder…

2. I Route the Drums into the Instruments by dragging from Drums Router to Instruments Router (red arrow below is drag action). This creates a Receive in the Instruments Folder.

3. The options for the Instruments Receive are typically as follows:

Note: Audio is coming from Drums 1/2 and is going into Instruments on 3/4 – and we don’t want Midi going in.

4. Now let’s add FabFilter Pro-C 2 to the Instruments Folder (track):

5. And ensure that the ‘Plug-in pin connector’ looks like this:

6. Now go into the Side Chain option in FabFilter Pro-C and select the ‘Ext’ Side Chain input. so that the detection path automatically uses the 3/4 input (Drum receive).

That’s it, I now see FabFilter Pro-C just receiving input from the Drums Folder:

The above method could be used for individual instruments (no need for folders), and don’t forget you can add multiple instances of FabFilter Pro-C to a Track. so, you could have Side Chain from multiple sources (receives) – for example on channels 5/6, 7/8 etc).

Also, you could Send the Drums to individual Instrument Tracks (that each have Pro-C added) to have finer control over the Ducking of each Instrument with the Drums as a source.


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