++pitchsift manual

+pitchsift – pitch shifting and vocoding

The plugin +pitchsift is the classic phase vocoder based pitch shifter with a number of enhancements. Pitch shifting is provided with a large range, 4 octaves up and 4 octaves down. At the far extremes of pitch shifting, the resultant sound bears little resemblance to the original. The highest quality pitch shifting comes when shifting no more than an octave, and with 1024 or 2048 bands.


pitchshift – This adjusts pitch up or down up to an octave. Pitch is displayed either in 25 100 cent increments or in 25 selected just intervals. 

just/12tet – This switches the pitchshift knob from just tempered pitches to 12 tone equal temperament.

cents – This adjusts pitch up or down 100 cents. Cents are based on 12 tone equal temperament.

octave – This adjusts pitch up or down 3 octaves. This control is stepped, for quick harmonically coherent changes.

fftout/sineout – Internally the plugin has two synthesis engines, fft out or sinebank out. One is based on a bank of sine wave oscillators, and the other is based on an inverse FFT. These methods have a slightly different sound quality and greatly different CPU load. In the sine bank oscillator synthesis method, amplitude and frequency are linearly interpolated for each block of samples. With this method, the amount of computation needed naturally goes up as the number of bands is increased. The inverse FFT method is more efficient, but distorts when more than one partial falls into a given FFT band.

partialgate – This eliminates all harmonics below the level of the gate, and at extreme settings can reduce any sound to a small number of sine waves. This harmonic gating is a nice transformation alone, or when combined with pitch shifting.

bands  This controls the number of bands used in pitch shifting. More bands results in better pitch resolution and accuracy, but worse time resolution. Extreme setting can cause a lot of frequency or time distortion.

sieve – This button turns on the pitch sieve harmonizer. The pitch sieve is controlled either by a MIDI input, or by the 3 octave keyboard between the knobs and buttons. An open or split note will let that note and its harmonics through the sieve. This harmonizer is most effective when using inverse FFT synthesis.

harmonics – The number of harmonics which will be let through the pitch sieve harmonizer. Negative values on this knob let through only odd harmonics.