Production Techniques – Parallel Compression, Haas & Reversing

Over the past few months i have been producing my own personal track and during the mixing stages i have used different techniques to make the mix more coherent and dynamically appropriate for the genre. All of the processing was done on Logic Pro 9 using only the stock plugins.

Parallel Compression

Parallel compression or New York compression, is a dynamic range compression technique used in the later stages of mixing to even out the dynamics in stereo percussion buses, electric bass or even vocals. in a nutshell, Parallel compression is a form of upward compression and is achieved by mixing an unprocessed ‘dry’, or lightly compressed signal with a heavily compressed version of the same signal. What it does is bring the highest transient peaks such as kicks and snare and brings them down for the purpose of dynamic range reduction. by reducing the dynamic range, it brings up the softer sounds, adding audible detail for smaller things such as hi-hats and shakers.

i used parallel compression on my percussions to add an extra layer of thickness to the major transients and backbone of the 4/4 signature. Here is 12 bars of my own percussion stem without parallel compression. The kick and snare are rather loud compared to the hats when the smaller percussions elements kicks in.

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For the first step,  i duplicated the drum stems i already have and colour coded them for the parallel compression.

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For the heavily compressed track, i used a very harsh brickwall compression settings. The knee and ratio are maxed to their respective setting so that any signal coming in is dynamically squashed as soon as possible, especially with the absurd ratio rates. The attack and release is relatively quick so that the main transients are processed quickly since the track is mainly composed of quick percussive transients.

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After the compression i adjusted the the wet signal with the dry signal and created an appropriate balance between both of the signals.

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After applying parallel compression, not only did it make the other elements of the stem more dynamically coherent, there were also minor changes to the envelopes of the percussions in terms of dynamics. The decay of the kicks and snares sounded louder and provided more

Haas Effect

The Haas effect or Precedence effect is an effect that is achieved by using a time delay trick on a signal to give it a sense of stereo spaciousness.

This is typically done when a sound is followed by another sound and is separated sufficiently by a short time delay. By creating an artificial lag listeners perceive a single fused auditory image, its perceived spatial location is determine by the position of a sound based on which ear perceives it first and its successive reflections (arriving within 1-35 ms from the initial sound) and will give the perception of depth and spaciousness.

To achieve the Haas effect on logic 9 i used the stock sample delay plugin. The plugin is straight forward to use and only features 2 controllable parameters for delaying the left or right signal. The delay works via samples not ms but a general conversion equivalency of 1000ms = 44100 samples is taken instead. The trick was just to make the delay not noticeable and so precise ms changes were not needed but only objective choices that fit the track.

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The vocals for the track before the haas effect was generally very mono and sat comfortably well in the centre. However by achieving this effect there is a sense of stereo wideness filling up the panoramic stereo quite well. It also works well with glue-ing the vocals with the synths since both were wide, leaving the percussions to fit in the centre.


Reversing is a production technique which is commonly used to create tension and create an artificial slow attack when dealing with transients. Reversing can be used on any audio source to either create an interesting effect and is used

For example reversing sounds such as white noise or vocal breaths can be used as a riser or a down riser to provide energy in a track which is commonly used in high energy genres such as dance music. Another interesting use of reversing is the topic of back-masking and the idea of deliberately reversing phonetics to create secret messages. Elements such as piano scan also be reversed to create a swell or a interesting melodic effect and is used to create a really trippy and uneasy sound.

Going back to the use of risers, here i reversed a crash cymbal to create an artificial swell and is used build tension and also used as a transition in the next section.

Reversing in logic can be done in sample editor under the functions tab. Reversing in logic is a destructive method and so i duplicated the file and used the copy as my reversed signal. Ive then inserted the dry crash at the end of the reverse transient to create the effect of a cymbal being scraped.

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Ive also reversed the toms for a more interesting effect as well as the crash and is highlighted in red. The toms acted as a counter act to the high frequency crash cymbal and provided a a low frequency rumble which gradually increased in dynamics. This gave a gradual increase in the tension and somewhat of a dramatic introduction into the actual tom samples.

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