5. Modulation plugins
Such effects as a chorus, a flanger and a phaser create audible “thickening” of the original sound through the use of a short time delay and phase modulations. They are capable of changing a narrow sound considerably by expanding it in width and bringing a noticeable movement between right and left channels. But be careful, along with that they greatly change the timbre of instruments what, for instance, in most cases will hardly be suited to mixing drums.
6. Delay and the Haas effect
Another common technique for widening a mix is the use of the Haas effect to turn some mono instruments into stereo. The effect is based on a particularity of human hearing which, as far as known, doesn’t distinguish the delay shorter than 30 ms. Copy the track with the instrument and pan both copies to the left and right to the max. Apply a time delay up to 30 ms (in some cases up to 40–60 ms) to one of the tracks. Such a short delay is not perceived by human ear as echo, and, as a result, we hear one but quite a wide sound. If you create AUX bus with delay plugin with a zero delay on one of the channels and 1–30 ms on another and blend such processing with the original mono sound, you may achieve some interesting results as well. This technique is fairly often used in our audio mixing and music mastering demos.
7. Panning contrasting sounds
The most noticeable widening effect can be received by hard panning two different instruments, for instance, a guitar lick and an organ part which has the rhythmical line approximately at the same pitch. The main secret of a truly wide sound on mixing mastering audio is indeed different sounding of right and left channels.