Announcing VCV Mid/Side, an encoder/decoder for mid/side stereo processing. Included with VCV Rack—get it by updating your plugins.
When working with stereo audio, it is common to use cables for carrying both the left and right channels of audio, corresponding to sound playing through your left and right speakers. But there’s another way to think about stereo which is often more useful, flexible, and intuitive than left/right signals.
With mid/side stereo, the mid signal is the average of the left/right channels, and the side signal is the difference between them. If your side signal is silent, you will have an entirely mono signal, as if a performer is playing directly in front of you. As the side signal becomes louder, the stereo field widens and more detail happens to the left and right of the sound stage. By adjusting the side level, you can easily control the stereo width of a complex stereo signal.
Mid/side processing is useful for many applications, such as allowing mono audio processors to handle stereo audio by converting to M/S, processing just the mid signal and decoding M/S back into L/R. If the stereo width is small, this can be a good approximation of a full stereo effect.
If you like math, the conversions are achieved by these formulas.
M = (L + R) / 2
S = (L - R) / 2
L = (M + S) / 2
R = (M - S) / 2