To achieve parallel compression, create an aux track and send the signal to it from the audio track you want to use. When it comes to quiet input signals — those which fall below the compressor's threshold — the compressor obviously won't be applying any gain reduction. The usual way to achieve this is to introduce 'make-up gain' at the output of the compressor. That’s why parallel compression is often used on drums and percussion. You can use this technique on ANY instrument including vocals, bass, electric guitars, whatever! Parallel compression is an incredibly useful pro technique to have in your toolbox. This is discussed in detail in a Q&A response published in the June 2013 issue: www.soundonsound.com/sound-advice/q-parallel-compression-revisited. Parallel compression is a powerful tool for shaping your dynamics. All contents copyright © SOS Publications Group and/or its licensors, 1985-2020. The overall result is that the dynamic range has been reduced, again, but this time the peak level is restored to the same as the input while lower-level signals have been raised — so the quiet bits have been made louder. var abkw = window.abkw || ''; Figure 3: By adding make-up gain to downward compression, you shift the dynamic range, to give you greater level at the compressor's output, but the range itself is still compressed in the same way. That doesn't really look much like upwards compression, does it? Compressors are available in myriad different forms, using feed-forward or feedback control paths, with RMS- or peak-weighted side-chains, and even more variations of audio-attenuation device, such as opto attenuators, diode rings, vari-mu valves, solid-state VCAs… and the list goes on! It could be your next secret weapon technique! From a practical perspective, then, the key to effective parallel compression is to ensure that the compressor threshold is set comfortably below the lowest signal level to be processed. In that way, the source's dynamic range is fully contained within the true upwards compression region of the transfer characteristic. Of course, this requires a compressor that behaves nicely when applying a lot of gain reduction and doesn't generate any distortion products, which some do. Web site designed & maintained by PB Associates & SOS. Try parallel compression on percussion and experiment with high ratios and low thresholds as you’re dialling in the settings of the compressor on the wet channel. This is a technique I've known about for quite some time, and have been using to varying degrees for the past five years, but have only recently fallen in love with. The 'ladder diagram' (Figure 1) is a convenient way of describing the relationship between signal levels at the input of a compressor, and those at the output. Note, however, that this is achieved without disproportionately boosting the very quietest part of the signal — ie. Above the threshold, then, the curve follows exactly the same general shape as true upwards compression. LANDR is the creative platform for musicians: audio mastering, digital distribution, collaboration, promotion and sample packs. To try to make this 'bowed' compression slope more obvious, I increased the amount of dynamic range reduction by adding another pair of parallel compressors, totalling three in all, and the result is shown in the Figure 7. In other words, this simple parallel compression arrangement raises the level of quiet signals by 6dB. That’s why parallel compression is often used on drums and percussion. However, the action of turning the level down (and back up again afterwards) isn't instantaneous; it takes place over a timescale that is governed by the compressor's attack and release time constants. Using parallel compression with a single compressor would raise the noise floor only to -74dBFS, and even using three parallel compressors for more squash would only raise it to -68dBFS — which is far more acceptable! Our blog is a place for inspired musicians to read up on music & culture, and advice on production& mastering. Incidentally, a 'hard-knee' compressor, like the one used for these measurements, switches abruptly from doing nothing to squashing the audio, and that is revealed by the very distinct change of angle on the transfer curves. So, using … Parallel compression settings One of the biggest benefits of parallel compression is being able use to intense compression settings without completely destroying the dynamics of your source. Get the best of our production tips and news, weekly in your inbox. If you’re struggling to get what you need from traditional in-line compression or you’re just looking for a more creative approach to dynamics, give parallel compression a try. the noise! Louder elements — those above the -20dBFS threshold — are compressed, as before, by a ratio of 2:1, but because the make-up gain is counteracting the compressor's peak level reduction, the highest input level appears at the output at the same -5dBFS. The red dotted line is the transfer curve for the direct path on its own again, and the purple line is the output from a single parallel compressor configuration.