X

Chapter 6 Filter eects 12 2
EVOC 20 Filterbank
EVOC 20 Filterbank overview
EVOC 20 Filterbank consists of two formant lter banks. The input signal passes through the two
lter 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 lter bands with the
Formant Shift parameter. You can also crossfade between the two lter 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.
Output
parameters
Formant Filter parameters
Modulation parameters
•
Formant Filter parameters: Control the frequency bands in the two lter banks—the upper,
blue, lter bank A and the lower, green, lter bank B. See EVOC 20 Filterbank Formant Filter on
page 123.
•
Modulation parameters: Control how Formant Filter parameters are modulated. See EVOC 20
Filterbank modulation on page 124 .
•
Output parameters: Control the overall output level and panning of the EVOC 20 Filterbank. See
EVOC 20 Filterbank output parameters on page 125.
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 dierent 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.