EVOC 20 Filterbank consists of two formant filter banks. The input signal passes through the two filter banks in parallel. Each bank features level faders for up to 20 frequency bands, allowing independent level control of each band. Setting a level fader to its minimum value completely suppresses the formants in that band. You can control the position of the filter bands with the Formant Shift parameter. You can also crossfade between the two filter banks.
The EVOC 20 Filterbank interface is divided into three main sections: the Formant Filter parameters section in the center of the window, the Modulation parameters section at the bottom, and the Output parameters section along the right side.
Formant Filter parameters: Control the frequency bands in the two filter banks—the upper, blue, filter bank A and the lower, green, filter bank B. See EVOC 20 Filterbank Formant Filter.
Modulation parameters: Control how Formant Filter parameters are modulated. See EVOC 20 Filterbank modulation.
Output parameters: Control the overall output level and panning of the EVOC 20 Filterbank. See EVOC 20 Filterbank output parameters.
A short introduction to formants
A formant is a peak in the frequency spectrum of a sound. In the context of human voices, formants are the key component that enables humans to distinguish between different vowel sounds, based purely on the frequency of these sounds. Formants in human speech and singing are produced by the vocal tract, with most vowel sounds containing four or more formants.