What is Phase? The basics of Phase Alignment and Cancellation
What is Phase, and why is Phase Alignment so important, particularly when dealing with low frequencies like kick and bass sounds.
The phase of a waveform refers to its starting point, when two waveforms are playing at inverted phase of each other, the result is complete audio cancellation.
Furthermore, for every degree that the waveforms are out of phase, the result will be a varying amplitude of the resulting audio signal.
The effects can be accounted for when dealing with static waveforms, however if you look at the waveform of a kick drum – the phase changes throughout the duration of the sound and only becomes stable in the release stage.
This means that when layered over a static bass sound, it’s most likely throwing the amplitude of the bass all over the place, maybe even cancelling low frequencies at certain points.
We definitely don’t want that, and this is why using both a sidechain or “ducking” effect and considering, the phase of your waveforms when they do overlap, will make the low-end of your track sound much more stable.
Let’s get down to business…
Using a plugin such as LFOtool is a great way of cleaning up overlapping parts however when used too heavily it can turn a “rolling” bassline into a “galloping” bassline, and that may change the whole vibe of your track.
Creating less of a curve, while maintaining phase alignment will give you a cleaner sounding roll-off.
Keep in mind, these diagrams are just for reference, your bass sound probably won’t look like this
Now, it’s not as simple as tweaking the phase parameter on your plugin, as a large number of plugins create a click at the beginning of a Sine wave when it doesn’t start at a zero-crossing (i.e. 0°, 180° or 360°).
For this reason, I like to use an external plugin faTimeAlign to shift the output of the synth in time by a few samples – keep in mind the human ear can only really start to differentiate time differences around 25-35ms you’ve got some space to work with.
For a detailed walkthrough on Phase Alignment and Cancellation check out the video here: