Parallel Compression: A Powerful Technique in Music Production

May 21, 2018

[Editors Note: This article was written for the TuneCore Blog by our friends at SoundOnTime – a blog for music production enthusiasts.]

In the world of music production, compression is a widely used technique. In order to raise the overall level of a certain signal to make particular elements pop out in the mix, it proves to be a very efficient one too. However, most beginners don’t really know how to implement this technique effectively without compromising the end result of the mix.

An underestimated technique which directly stems from the aforementioned one is parallel compression. This technique produces results that are as satisfying, (if not better), than traditional compression. In turn, this article will attempt to precisely explain what parallel compression is, why you should consider it, its pros and cons, and how it should be properly implemented in a mix-down.

What is Parallel Compression?

The implementation of parallel compression is one of the most effective and widely practiced techniques in music production. But, what really parallel compression, really?

Shortly said, parallel compression is the combination of an uncompressed (or slightly compressed) signal with a more heavily compressed version of itself. This provides an increase in average level of that signal without the resultant compression artifacts.

How does this really happen?

Basically, by creating a second identical signal – via an auxiliary send, bus or group output on a console – any type of sound or group of sounds can be transmitted to a compressor that will process with parallel compression. What this means is that the compressor is processing the ‘duplicate’ of the signal, rather than the signal itself, which is then sent back into the console on a separate fader.

Here is a video that provides additional information:

Why Should I Add Parallel Compression?

One of the main advantages of parallel compression is that this technique can be used to considerably raise low-level signals without compromising the sonic integrity of that signal’s transient peaks. Sometimes, you would want compression artifacts, since they can be a crucial ingredient for the creation of a unique sound. However, most of the times, “New York Compression” (another name for parallel compression) is best since it can help you produce an invisible form of compression.

Parallel compression will help you raise the overall level of your signal without destroying any particular peaks of the signal in the process. Peaks of a particular signal are the most fragile components of a dynamic sound. Therefore, any change in the waveform’s envelope, especially if your compressor is not qualitative or inadequately used, can jeopardize the overall quality of your sound. In this circumstance your compressor settings will act quickly or slowly to allow the peaks of your sound to pass wholly or partially through.

As an example, one of the elements you sometimes feel should be more powerful during the mixing stage are the drums. Often, the drums, whether they are sampled, triggered or recorded in studio, lack a little extra punch even if they have already been through compression. Raising their volume cannot simply be achieved by driving your drums harder, since that wouldn’t contribute positively to the overall mix. In these circumstances, parallel compression can be useful in order to add the anticipated aggressiveness of your drums during the recording stage.

One last thing to keep in mind is that processing tools are available to solve specific issues. As with other available tools, don’t use them simply because they are available. Why don’t we turn every element of the mix up to maximum volume, distortion to every single element, reverb to the bass, maximum stereo width ? Simply because it wouldn’t produce a satisfactory result.

How to implement Parallel Compression?

  1. Buss the drums, and maybe even the bass, to a stereo
  2. Hit the compressor fairly hard—at least 10dB or more if it sounds
  3. Return the output of the compressor to a pair of fader inputs on the console or two additional channels in your
  4. Add a pretty good amount of high end (6 to 10dB at 10kHz or so) and low end (6 to 10dB at 100Hz or so) to the compressed
  5. Then bring up the fader levels of the compressor until it’s tucked just under the present rhythm section mix to where you can just hear

The rhythm section then sounds bigger and more controlled without sounding overly compressed Here is a video which demonstrates the process:

Here is another video that underlines “two secrets” to effective parallel compression:


Conclusion 

As you have seen, parallel compression proves to be a very useful technique when it comes to raising the signal of a certain track. It contributes to a sharper and more aggressive perception of the sound you are treating. If it is an underestimated technique, it should also not be overused, since it isn’t always the best option. However, for drums and vocals, it is an unmistakable technique to improve the overall quality of the sound.

Tags: featuring mixing music production parallel compression