Kim Lajoie's blog

Parallel processing

by Kim Lajoie on August 15, 2013

Recently I’ve been doing more parallel processing in my mixes.

It’s particularly useful for low-track count mixes, where each track has to have a rich and multidimensional sound. Contrast with high track-count mixes, where the goal is the opposite – to reduce each track to a one-dimensional caricature of itself so that all the tracks can blend well together.

Of course you’ve heard of parallel compression. Make two channels for a track (either duplicate the track or send to an aux track / group / bus). One channel remains relatively dynamic with little or no compression. The other channel is heavily compressed. On its own, parallel compression is not very interesting. But things get very interesting when each track has a different tone (with EQ settings, or other processing). When both channels are balanced, the more dynamic channel becomes more prominent during louder passages and the less dynamics (more compressed) channel becomes more prominent during quieter passages.

I’ve been using this as a form of dynamic tone control, except with much more natural results than a dynamic EQ (where the gain of each band is controlled by an envelope follower). In a recent mix, I wanted a juicy compressed vocal sound, but the compression was bringing up too much mouth noise and other background sounds in between phrases. I duplicated the track and brightened the more dynamic channel and slightly darkened the compressed channel. By carefully balancing the two channels, I achieved the thick compressed sound I was after, without drawing too much attention to the extraneous sounds. It also sounded much more natural than using an expander or dynamic EQ because the brightness of the vocal responded naturally to the actual original dynamics of the performance.

For a more extreme example, I was working with a very percussive acoustic guitar performance. The artist wanted his palm taps to resonate like a kick drum. Simply boosting the low end brought up too much string resonance and made for a very muddy sound. I duplicated the track and highpassed the primary one at about 120Hz to maintain a fairly natural tone and character. I didn’t compress or processes this one very heavily. The duplicate, however, was lowpassed at about 120Hz, leaving nothing but the bass. This channel was heavily gated to cut out the mud and emphasise the rhythm. I also applied some heavy dark saturation to make the sound thicker.

There are certainly some creative uses for parallel processing. Let me know – do you use parallel processing? If so, how? Leave a comment.


5 thoughts on “Parallel processing

  1. alex says:

    I use parallel processing in Ableton live with the help of chains within audio effect racks on the same track, no need for a duplicate one. Very conveninent

  2. Jordan says:

    I like to parallel process my Bass for rock mixes.

    Much like you did with the acoustic guitar, I hi and lo pass 2 tracks of bass, then fuzz up the midrange while keeping the low bassy stuff clean, then blen these signals for a nice thick, soupy bass track

  3. Kim Lajoie says:

    I haven’t used Live, but the effect racks look pretty neat.


  4. Kim Lajoie says:

    Dual-band processing for bass is pretty common. You could also compress or lightly saturate the bottom end as well, to make it more thick and solid, without modifying up the midrange character too much.


  5. Tyler says:

    Ditto on the racks in ableton for parallel processing….although I always worry that I’m introducing phase a when I do so.

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