Toolkit

Parallel compression

This month, let’s look at a technique used by industry pros to add power, depth and ‘inflation’ to mixes but which remains misunderstood by many. Compressors – in both hardware and software forms – provide dynamic range control, narrowing the volume gap between quiet and loud signals, before letting you set an overall volume for the sound you’ve compressed.

It’s a myth that compressors just make signals louder; in reality, the approach to dynamics range control most compressors use is called ‘downwards’ compression, whereby compressed signals are attenuated (brought down in volume) by a compressor’s threshold and ratio dials. It’s only at the output stage, via the use of the make-up gain control, that you can choose to boost the volume of your freshly compressed signal, giving you choice over how loud each sound should be.

However, today we’re looking at parallel compression techniques, which, whilst using the same compressor functions, operate ‘alongside’ a track’s main signal flow to add a second, compressed signal under the first. As signals which have been set up as parallel, secondary channels in this way play a supporting role, they can often employ more extreme compression settings than a ‘main signal’ allow. In fact, the artefacts and hyper-squashed sound of more brutal compression settings are often a benefit when working with parallel signals, in ways which would often prove unnatural using source sounds on their own. But we won’t just talk about when these treatments can prove useful, we’ll go further, using parallel compressors in series using multiple instances; and we’ll work with these parallel channels when further enhanced by other plugins too. Mostly, we’ll see just how much more power, punch and presence can be added to a mix via the use of parallel compression, using this technique to make certain parts within a track pop into the foreground of a mix, so you feel closer to the musical action.

In general terms, any stereo compressor will let you produce parallel compression treatments but we’ll also look at the benefits of working with parallel multi-band compression effects, enhancing specific areas of the frequency spectrum with bespoke dynamic range reduction settings. Check out this month’s video to see this in action. Perhaps the best-known use of parallel compression is on drum beats, an approach referred to as ‘New York Compression’. We’ll see this in the three-step walkthrough, while the six-step walkthrough discusses using parallel compressors to enhance the lead vocal in a mix, as a track moves from one density of arrangement to another. As we’ll see, combining parallel compression channels with stereo widening tools, prodigious use of the pan dial, or coupling compressors to other effects for further sonic enhancement can help take your mixes to the next level.