Waldorf Rocket - Manual (Page 29)

Sound Synthesis Basics
29 Rocket User´s Manual
Filter Introduction
Once the audio signal leaves the oscillator, it is sent to
the filter. The filter is a component that has significant
influence on the Rocket’s sound characteristics.
For now, we’ll explain the basic function of a filter dis-
cussing the type used most commonly in synthesizers:
the low pass filter
The low pass filter type dampens frequencies above a
specified cutoff frequency. Frequencies below this
threshold are hardly affected. The frequency below the
cutoff point is called the pass band range, the frequencies
above are called the stop band range. The Rocket’s filter
dampens frequencies in the stop band with a certain
slope. The following picture shows the basic principle of
a low pass filter:
The Rocket’s filter also features a resonance parameter.
Resonance in the context of a low, band or high pass
filter means that a narrow frequency band around the
cutoff point is emphasized. The following picture shows
the effect of the resonance parameter on the filter’s fre-
quency curve:
Frequency
Level
Cutoff