SSL Duende Tutorial 7 – Parallel Compression

Tutorial 7 : Parallel Compression

Note to Pro Tools LE and M-Powered users:

Please set the H/W Buffer Size to 512 Samples. This setting can be found in setup>playback engine.
Also where this tutorial references the ‘drum’ track, please take this to mean the ‘dry bus’. Do not adjust the level of the ‘drum’ track level as it will result in the audio being out of sync.

Have you ever felt yourself wanting that compressed, pumping drum sound that still retains the dynamics of the playing? If you dial in the required amount of compression the kit just sounds flat and lifeless, yet if you back the compression off the intensity and energy are not there.
Parallel compression is technique that involves mixing the original uncompressed sound with a suitably compressed version of it.

The Duende Bus Compressor can be very useful in this situation. Drive it hard and you get that classic SSL compression sound, but mix this with an uncompressed version and the life and dynamics are retained.

Load the tutorial 7 DAW session;

Here are two tracks; drums and parallel bus. Play the track and get used to the dynamics of the unprocessed drum track.
This track is send to a sub-group (bus) via a pre-fade auxiliary send. This means that the level of the fader on the drums track does not affect what is sent to the sub-group. The send to the sub-group is set at 0db.

Now pull the drums fader all the way down and push the parallel bus fader up to 0db. Now you hear the same track being smashed by the Bus Comp. Under normal circumstances this would probably be far too much compression to use as the main drum sound in a song.

  • A low threshold and 4:1 ratio are used to obtain a large amount of gain reduction, about 20db on the peaks.
  • The attack is at 3ms which allows some of the initial punch of the drums to come through, but doesn’t hesitate too long before clamping down on the signal.
  • A very fast release of 0.1ms is used to cause the pumping effect.

Now you have the parallel bus ‘over’ compressed, push the level of the drums fader up until the overall sound regains some dynamic and clarity.
Mix the level of these two faders according to taste, depending on what you’re after.

This works because the parallel bus and the drums track are exactly in phase and time thanks to Automatic Delay Compensation available in most DAWs.

This technique can be used on any material, and can be considered an alternative way to work where the desired compressed sound can be mixed in to taste with the original uncompressed sound.