Follow along as we wire up this simple two-switch circuit that turns vocals off for instant instrumental mp3s. On any song where the track is equally mixed to left and right channels of stereo audio, the Sing-a-long Song Devocalizer will cancel them out, allowing you to isolate the instruments without the interference of song.
Make Magazine Executive Editor Mike Senese sums it up when he proclaims, “It’s mathematical!” and he breaks it down:
When songs are mixed from individual tracks, the waveforms of the isolated instruments and voices are added together to form the left and right channels of the stereo mix. Tracks can be panned left, right or center across the stereo field to create the illusion of space. Typically vocal tracks are placed in the center of the mix, which results in mathematically identical waveforms being sent to each of the left and right channels.
The devocalizer lifts the common ground for the stereo signals, and instead uses the opposite channel as the new ground. As a result, the signals are now 180 degrees out of phase from each other. Each stereo channel is added to an inverse copy of the opposite channel, resulting in any audio that is mixed to both channels being subtracted from the waveform.
Now see – and hear! – it in action:
Let us know what tracks you listen to that produce unique, anomalous audio effects, or which generate crazy digital, almost auto-tune-like vocals.