The Haas Effect – what it is, and how to use it in your tracks
The Haas Effect (also known as the Precedence Effect) is a psychoacoustic phenomenon named after Doctor Helmut Haas. What he discovered was that the human ear can’t easily distinguish between two separate sounds if they are heard less than 40ms apart. Instead, the two sounds are perceived by the human ear as a single sound with an added sense of depth and space.
The Haas Effect can be used by producers as an alternative to panning, to create more of a stereo image. Generally, it works better on sounds at higher frequencies such as hi-hat or shaker loops, but note that it should always be used sparingly with the specific purpose in mind of creating an interesting soundstage.
See below for an example of how to setup the Haas effect in Ableton Live using the stock Delay effect. Note that the Left and Right channels have been de-linked and set to an offset of less than 40ms. The Dry/Wet is turned all the way up, and the feedback all the way down. You can experiment with the amount of delay until you are happy with the sound.
See below for an audio example of the Haas Effect on a simple Hat loop, together with how it sounds in the mix:
Another more creative way to use the Haas Effect would be to use it on layered percussion sounds. For example if you had a clap sound hitting just before a snare you could use a longer delay on the initial clap, before drawing back towards the centre of the soundstage by using a shorter delay for the snare. Uses of the Haas Effect in production are not just limited to drum or percussion elements either. They could also be used to add depth and interest to a synth track for example. Generally IMO a slightly longer delay sounds better with synths, with shorter delays being used for percussion elements.
In conclusion, the Haas Effect is a simple and effective way to add depth to your mixes, and a great technique to have in your production arsenal.