Resonance, also known as “Q” or “emphasis,” refers to the property of a filter that amplifies or accentuates frequencies around its cutoff frequency. Resonance is an essential parameter in many filter modules, as it can significantly affect the character and timbre of the sound being processed.
When the resonance is increased on a filter module, the filter will start to emphasize and boost the frequencies near its cutoff frequency, creating a peak or a “ringing” effect at that point in the spectrum. This can result in a more pronounced or “sharper” sound, adding harmonics and making the filter’s effect more noticeable.
In some cases, when the resonance is set to a high level, the filter can self-oscillate, meaning it will generate a sine wave at the cutoff frequency even without an input signal. This self-oscillation can be used as an additional sound source in your modular synth or to create complex modulation signals when used at audio rates.
Resonance is a crucial parameter in sound design and can be used in various ways in modular synthesis:
- Sound shaping: Adjusting the resonance can help you sculpt the timbre of a sound, making it more or less pronounced depending on the desired effect.
- Creating formant-like sounds: By using multiple resonant filters in parallel and adjusting their cutoff frequencies and resonance, you can create vocal-like or formant sounds.
- Self-oscillation: As mentioned earlier, when the resonance is set to a high level, the filter can self-oscillate, generating a sine wave. This can be used as an additional sound source or a complex modulation signal.