Pro Mixing Series: Episode two: The Haas Effect
Tuesday, August 26th, 2008
For some of us this may be a very mysterious image: “panning” presets in a delay device of a sequencer DAW…
Well it IS a mysterious image until you check this article about the Haas effect.
Have you ever been so frustrated with a mix that doesn’t have life, wide stereo image and airy, “natural” space? Are you not getting enough depth in your mix? Have you added so much stereo reverb to add “space” to your mix that you end hating what you have done? Well… I have…
It is truly horrible getting every track in a mix sounding so “mono” after panning left and right different lines or instruments. It feels truly like there is something in the way from the original tracking to your final mix. The panning of some tracks helps very much to make a clear mix but sometimes that is just not enough to make things clear and certainly deeper, spacious, open and rich-sounding.
There is a solution to this lack of depth: The Haas Effect . It can take a simple mono instrumental or vocal line and give it presence or take it to the back of the mix, depending on how you use it and what other effects you add to the chain.
Basically, what you are doing with the Haas effect is making the listener’s brain to interpret the sound coming from a certain direction and angle in a way that is more natural to the ear than a simple panning adjustment. The Haas effect takes full advantage on the fact that we have TWO ears.
In real life, when a sound comes from the left it is received by the left ear BEFORE the right ear, so the brain interprets this difference as “a sound coming from the left”. The interpretation depends on how long is the delay between the two ears the less the delay, the more centered is the sound. This very short delay can be interpreted as a phase shift because the sound reaches first one ear and then the other. So, when there is no phase shift, no delay between the two perceived signals together are interpreted as dead center, with no panning at all.
We CAN use this psychoacoustic effect (the Haas effect) to print more depth and directionality into our mixes without even moving the panning control of the console! That’s why I put the snapshots from Ableton’s Simple Delay. You can make your own Haas effect presets in any delay that permits very, really shot delay times and also inserting a time shift between the two channels. The Haas effect is performed delaying one of the two channels (left or right) just a little bit, from a couple of samples to no more than 30 milliseconds (more in depth scientific info in the article from Wikipedia referenced above); the channel that reaches our ear first is the one that dictates where is the sound “coming from”, the later channel is interpreted as the natural tail of the sound.