Filter introduction – Waldorf Pulse 2 User Manual
Page 52

Sound Synthesis Basics
Pulse 2 User Manual
52
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 Pulse 2’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 frequenci-
es above are called the stop band range. The Pulse 2’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 Pulse 2’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
frequency curve:
Frequency
Level
Cutoff