Parallel compression is the defining technique of the iconic mix engineer Michael Brauer. Taking advantage of the differing tonal and response characteristics of a group of top compressor plugins, he shapes the tone and vibe of the vocal tracks uniquely and powerfully.
Although Brauer’s system is significantly more complex, parallel compression, in its essence, is compression as an aux effect. You don’t compress the source track directly. Instead, you compress a copy of the track or send it to a compressor on an aux track. (Alternatively, you can create parallel compression from a compressor plugin on the source track’s insert if it has a dry/wet mix control.)
In the mix, you have separate controls for the dry and compressed signals, letting you dial in just the right blend of processed and unprocessed audio. That allows you to add the flavor of a specific compressor to the source track without overly squashing its transients.
In this excerpt from “Michael Brauer Deconstructing "Friendly Fire,” he uses his “Brauerize” technique (see this article for a detailed description) to shape and mold the sound on a Ben Abraham vocal track.
Any Combination
Brauer’s version of parallel compression is unconventional. One reason is that the uncompressed vocal doesn’t go directly into the mix from its track’s output. It only gets in by way of the reverb and delay sends.
In this screenshot from Brauer’s Pro Tools template, the parallel vocal compressor tracks are in the light blue section.
Also, Brauer “plays” his compressors almost like an instrument. He knows the characteristic sound of each one and blends them to get the sound he wants. It’s almost like using compressors as EQs.
“I only use two or three of them, and there are, there are the times when I just use 'em all,” he says. “I don't particularly care what it takes to get that vocal sound because there are no rules.”
Brauer mixes the levels of each parallel compressor from his DAW controller.
If you want to dig deeper into Brauer’s template and are a puremix member, you can download it from the main page for the video, The Evolution from Analog to Digital, “Brauerize”©.
His Compressor’s Voice
All compressors attenuate signals that exceed the threshold, but that doesn’t mean they sound or work the same. Several factors give hardware compressors—or plugin emulations—differing sonic characteristics.
First, there’s the architecture—how the compressor goes about its business impacts its sound. For example, FET compressors (such as the 1176) use a type of component called a Field-Effect Transistor to mimic the behavior of tube circuitry. FET compressors don’t have threshold controls. Instead, attenuation gets triggered by the input level. They feature fast attack times and can create an aggressive sound.
In an optical compressor, a copy of the incoming audio gets sent to a transducer that turns it into light (hence the name “optical”). The more sound coming in, the brighter the light.
The light triggers an optical cell that controls the amount of gain reduction. As a result of this design, optical compressors tend to be relatively slow to react and thus impart more gentle characteristics to the sound. The classic LA-2A combines optical compression architecture with tube amplification to produce smooth, warm, dynamic control.
Another compressor type is the tube or “vari-mu” design. It uses tube re-biasing to attenuate the signal. The Fairchild 660 and 670 are classics of this type. Tube compressors can add considerable warmth to the signal when the tubes (or digitally emulated tubes) create saturation. Tube compressors also have a relatively slow response compared to FET or VCA compressors.
The Fairchild 670 is a classic vari-mu (tube) compressor.
A VCA compressor, which uses a “voltage-controlled amplifier” to govern attenuation, is the most versatile and user-adjustable type of compressor. As a result, VCA compressors offer a broader range of sonic possibilities.
Beyond the compressor type, another important factor is the specific design of a particular make and model. For example, the dbx 160 offers different sonic characteristics than other VCA compressors because of its proprietary circuit design and the type and quality of components that dbx chose for it.
And, of course, how you set the compressor significantly impacts its sound. If you dial in a fast attack and release and a lot of gain reduction, you’ll get a much different sound than if you use more moderate settings. And whether you’ve configured your compressor in parallel or as an insert will also change the results.
Choose a Flavor
In the following examples, we’ll listen to the differences between several models and types of compressors. We’ll use a simple drum loop, which makes it easy to hear the compressor’s effect by how it impacts the transients. The compressors are set up in parallel and have fairly aggressive settings.
First, here’s the uncompressed loop.
Next, the same loop is compressed by a Plugin Alliance Acme Opticon XLA-3, a model of an optical compressor with tube components (similar in design to an LA-2A). Both the bass and snare get somewhat squashed by it.
This time, the parallel compressor is a UADx 1176LN REV E plugin, a FET compressor with a very fast attack. Notice how the compression adds sustain.
The settings on the compressor plugins used in the examples.
This one features a UAD emulation of the classic VCA compressor, the DBX-160. It offers a tighter compression than the others, adding a unique “thwack” sound to the snare.
Finally, here’s a Waves Abbey Road RS-124 plugin, which is modeled from a variable-mu compressor used at Abbey Road Studios. Notice how it saturates the snare.