Location: STSideComp



The STSideComp is a straight forward, full parameterized compressor with a dedicated sidechain input stereo channel. It is designed as a VST effect for MacOSX and is specially created for and tested with Ableton Live as you can see in the Tutorial. I wrote the plugin because I was looking for a freeware solution but the only one I found did not sound well enough to me and seemed to be discontinued. You can use the plugin especially in modern music styles like House or Techno in order to gain the typical ducking effect, best known from French House. The underlying dsp algorithm deviates from code samples and notes I found at www.musicdsp.org. The plugin is licensed as freeware. Please note the technical details in the FAQ.


Current Version



01/14/2008 STSideComp_1.0.dmg Initial release, VST, Universal Binary

Tutorial on Ableton Live

Start the plugin by selecting it from your list of plugin devices and drag it onto the track you want to have the ducking effect on. In the screenshot this is track "1 Compressed".

Next go to the track with the trigger signal (like a bassdrum) and route the audio output of this track to "1 Compressed" -> "3/4 STSideComp". In order to hear the trigger signal itself simply create a new audio track, set the audio input of the track to the trigger track and switch the monitoring of the new track to "In".

Finally you can adjust the parameters to your needs. It is very important to switch "Use SC" to True in order for the plugin to use the dedicated sidechain input as trigger signal for the compressor. Otherwise the plugin works like a normal compressor on the track's audio signal itself. All other parameters should look quite familiar to you.

Have fun!


Which tools and interfaces were used to develop the plugin?

The plugin was built and debugged with XCode 2.2 and Ableton Live 6.0.10 on an Intel MacBook Pro with MacOSX 10.4.11. The plugin has been written from scratch in plain C++. It is compiled against VST SDK 2.4 rev2. The installer package was created with Mac's own PackageMaker.


This is my first software project in the scope of audio processing. If it is useful to you, or even if not, please let me know. I want to get in contact with other people working on dsp and music software in order to exchange experiences and learn from them. Please don't hesitate to write me an eMail!

Copyright © 2008 Oliver Walczak. All rights reserved.