Resonant low-pass filter
8.1.3.3 The resonance
A second setting to compliment the cut-off frequency is the resonance (you will also find it called “emphasis” or “Q” (for Quality of filtering) elsewhere).
The resonance is able to amplify frequencies close to the cut-off frequency. Then the other frequencies remaining are either unchanged (below the cut-off frequency) or reduced (above the cut-off frequency). Resonance will also cause the frequencies below cut-off to be reduced, which is one factor in the resonance sounding more pronounced. On the Jupiter-8 you can increase the resonance through the “RES” Slider.
When you increase the resonance, the filter becomes more selective, the cut-off frequency is amplified, and the sound will begin to “ring” at higher settings.
The resonance amplifies frequencies close to the cut-off frequency
With a high resonance level, the filter itself will begin to produce a sound close to a sine waveform with no outside input, which is referred to as self-oscillation. At this stage, the use of a key follow is very important as you can create a melody by tuning the cut-off frequency of the filter with the frequency of the oscillators.
ARTURIA – JUPITER-8V – USER’S MANUAL | 95 |
