ABSTRACT
When you combine multiple sounds, they will interact. Where the frequency components that make up these sounds overlap, attenuation or amplification will take place. What will happen depends on the phase relation of the overlapping components. Phase is a measure of how far a wave of a particular frequency has advanced in its repetitive cycle. Random phase relationships between overlapping frequencies aren’t problematic in mixing, but as soon as there is a fixed phase relationship between the sounds you’re adding, the interaction can result in harmful filtering of the combined audio. Avoiding this effect in recording and mixing will help to keep your mix powerful and natural-sounding.
