Ultrabeat filter section in MainStage

The filter can operate in several modes, allowing specific frequency bands to be filtered (cut away) or emphasized.

• In MainStage, to select a filter type, click one of the following buttons:

  • LP (lowpass): This filter type allows frequencies that fall below the cutoff frequency to pass. When set to LP, the filter operates as a lowpass filter. The slope of the filter can be set to 12 or 24 dB/octave in LP mode.

  • HP (highpass): This filter type allows frequencies above the cutoff frequency to pass. When set to HP, the filter operates as a highpass filter. The slope of the filter can be set to 12 or 24 dB/octave in HP mode.

  • BP (bandpass): The frequency band directly surrounding the center frequency (set with the Cutoff knob) is allowed to pass. All other frequencies are cut. The Resonance parameter controls the width of the frequency band. The bandpass filter is a two-pole filter with a slope of 6 or 12 dB/octave on each side of the center frequency of the band.

  • BR (band rejection): The frequency band directly surrounding the center frequency (set with the Cutoff knob) is rejected, while the frequencies outside this band can pass. The Resonance parameter controls the width of the rejected frequency band.

  

Most filters don’t completely suppress the portion of the signal that falls outside the frequency range defined by the Cutoff parameter. Frequencies that are located close to the cutoff frequency are generally reduced less than those that are farther away. The higher the slope value, the more apparent the level difference is between frequencies that are near to the Cutoff frequency and those that are farther away from it.

• In MainStage, click the 12 dB or 24 dB button. The slope (curve) chosen for the Filter expresses the amount of rejection in decibels per octave. The steeper the slope, the more severely the level of signals below the cutoff frequency is affected in each octave.

  

• In MainStage, rotate the Cutoff Frequency (Cut) parameter to control the brilliance or determine the center frequency of the signal.

  • In a lowpass filter, the higher the cutoff frequency is set, the higher the frequencies of signals that are allowed to pass.

  • In a highpass filter, the cutoff frequency determines the point where lower frequencies are suppressed, with only upper frequencies allowed to pass.

  • In a bandpass/band-rejection filter, the cutoff frequency determines the center frequency for the bandpass or band-rejection filter.

• In MainStage, rotate the Resonance (Res) parameter to emphasize or suppress portions of the signal above or below the defined cutoff frequency, or to determine the width of the band that surrounds the cutoff frequency.

  • In a lowpass filter, Resonance emphasizes or suppresses signals below the cutoff frequency.

  • In a highpass filter, Resonance emphasizes or suppresses signals above the cutoff frequency.

  • In bandpass/band-rejection filters, resonance determines the width of the frequency band that surrounds the center frequency (set with the Cutoff Frequency parameter).

The output signals of both oscillators, the ring modulator, and the noise generator are sent to the central Filter section (if not bypassed with the various Signal Flow buttons). The Filter section offers a multimode filter and a distortion unit. Sounds are passed through the filter and distortion unit as determined by the direction of the arrow found in the center of the filter section.

• In MainStage, click the arrow to change the signal flow order between the following:

  • First the Distortion unit, then the Filter circuit (arrow pointing up)

  • First the Filter circuit, then the Distortion unit (arrow pointing down).