The High Pass Cutoff limits the low frequencies that are played. It lets the high frequencies ‘pass’ or ‘get through.’ This is similar to turning down the bass knob on a stereo.
High Pass Cutoff: The high pass cutoff value represents a frequency between 0% and 100%. The default is 0%, which allows all frequencies to pass. 100% is essentially silent and does not let any high frequencies be heard.
High Pass Resonance: As this value increase, the overtones near the cutoff are boosted. The result is that the cutoff frequency is much louder than the rest of the audio being filtered.
IMPORTANT: The High Pass Cutoff works hand in hand with the High Pass Resonance. The HIgh Pass Resonance level will not be audible if you haven’t adjusted the High Pass Cutoff!
Tips:
q To use the resonant filter creatively, try a resonant filter sweep. To do this, set the Resonance envelope at 200 and create a Cutoff envelope that rises and falls slowly. Since the resonant value is relatively high (200), as the cutoff goes up and down you should distinctly hear the "resonant peak" follow the cutoff, with its characteristic sound. For example, the famous wah-wah pedals used by guitarists, makes use of resonant filter sweeps back-n-forth, with the cutoff controlled by the foot pedal.
q If the resonant setting is cranked all the way up to 256, the filter goes into a state called "self-oscillation" and produces a ringing-whistling tone. ATTENTION: this can be very loud and overwhelming, so please watch your audio levels as it can be dangerous for your ears and your speakers!!
q Using resonant filter sweeps on synthesizer melody lines can make some very musically compelling timbre and tone changes, to signal a transition, a buildup or a bridge.
* The cutoff % is a mapped logarithmically from 200 Hz to ˝ sample rate.