How to Use Parallel Compression in Pro Tools

How to use parallel compression in Protools

In this video, Grammy Award-winning recording engineer and Dark Horse Institute instructor, Steve Lamm, shows you how to achieve superior sound affects using compressor controls in Pro Tools. This feature helps you manage the decibel level for a measured length of time.

What Is Parallel Compression?

When you split an audio signal, two copies are created—one is compressed and the other is not. Sometimes audio compression can produce a radically unintended output at its loudest part from the initial attack. The transience can sound too dull and cut off due to being processed too quickly. Therefore, the compressor’s function is to split the signals and ensure the audio never gets too loud on one copy, while the second copy remains unaffected. This enables you to pull up the volume on the compressed signal and the unaffected signal, so that the transience makes its way through both. The end result will produce excellent volume control without loss of clarity.

Thicker and Fuller Sound

For affect, you can achieve a thicker and fuller sound with one signal and yet still maintain the definition, tone and character of the original performance. Sometimes too much compression can sound heavy, causing “pumping” and loss of transience. To avoid this outcome, adjust the amount of compression for a push-pull affect, by taking the direct signal and blending it back in with the highly compressed signal. This maneuver will maintain the sharpness of the attack and high-end transience.

To implement this affect easily, first use the Prefader Aux Send functionality in Pro Tools to send a new track. Since it’s a Prefader, the volume will never change. Next, put the compressor on the second track, then turn it down until you have adjusted the compression exactly the way you like it.

This technique is great for percussion instruments such as drums and acoustic guitar, and vocals as well. It will result in an overall smoother audio outcome without losing definition, by taking one signal and making it fatter and fuller sounding, while maintaining the tone and character of the original performance.

As always, remember to trust your instincts first when it comes to sound. Your ears are your best tools.

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