CROSS FADES: EQUAL GAIN AND EQUAL POWER

If you’re lining up audio files whose region edges touch, you need to find a way to smoothly transition from one to the next, without the ‘jigsaw piece’ edges producing unwanted clicks. There are two similar (but different) ways to do this. The first uses a standard ‘crossfade’, known as an Equal Gain crossfade, where the first audio file continues to play for a short while after its end point occurs, playing on for the next few milliseconds (or seconds, depending on the fade length). Simultaneously, the adjoining piece of audio will ‘start early’, fading up to its official start point where one region becomes another, exactly like the crossfader control on a DJ’s mixer. The only issue here is that depending on the nature of the audio files, the ‘energy’ in one file might considerably outweigh the other, meaning that an Equal Gain crossfade can sound unbalanced, with the dominant volume of one audio file remaining over-strong through the crossfade. Equal Power crossfades address that balance by ensuring an even level of volume throughout the fade. However, what happens when you’re crossfading between two ‘of the same’ audio files? You might have decided you want to create a ‘sustained’ section from a short slice of audio and you’re looking to select that area, repeat it multiple times and crossfade between the repeats. If the musical content is ‘coherent’, whereby the waveform of one file is the same as the following one, an Equal Gain crossfade will usually produce a smoother result, avoiding a volume ‘boost’ in the middle of an Equal Power crossfade. Experiment with both fade types to choose the one which sounds most musical.