Window Reference Filter Page |

The audio signal from the Keymap Page feeds the Filter Page. If the filters are switched on, the signal is processed by the filters, otherwise the filters are bypassed.
Note: You don't need to use the filters if your Instrument design doesn't call for them. In fact, the filters contribute significantly to the synthesizer's CPU processing load - so if you don't need the filters, you should switch them off. To switch the filters off, click the small light next to the large Filter Page button to turn it off: Notes: If you want to use any stereo Samples in an Instrument, you'll probably want to avoid using the Filter. If you're going to mix mono and stereo Samples in the same Instrument, you'll probably want to avoid using the Filter. If you want to use the Filter on an Instrument, you'll have to use mono Samples. This is all because whenever an Instrument is playing a stereo Sample, the Filter is bypassed. As a result, bad-sounding artifacts can occur when a filtered Instrument switches from a mono Sample to a stereo Sample, or vice versa. About the Filters
The Filter Page contains two different filters, acting in series:
The Comb Filter has controls for the peak frequency spacing and resonance, and can be made to track the pitch of the notes that the Instrument is playing (see Track Pitch). Note: When the Tone Control setting is negative, the Comb Filter is bypassed. The Tone Control is a gentle high or low frequency rolloff filter with a Depth setting: When the Tone setting is positive, the Tone Control rolls off high frequencies. When the Tone setting is negative, the Tone Control rolls off low frequencies, and the Comb Filter is bypassed.
Both the Comb Filter and the Tone Control can be modulated (see Modulation Page).
Note that this filter set is a little different from most synthesizers and samplers, which usually use a resonant lowpass filter.
Tip: To approximate a conventional lowpass filter, set the Comb Filter for very wide peak frequency spacing, so that one cycle of the comb spreads out over the whole frequency spectrum. Working with the Filter Page Comb Filter
You can set both of the comb filter's parameters (peak frequency spacing and resonance) at once by clicking on the handle (small square) in the large display and dragging:
To change the peak frequency spacing, drag the handle left or right. Alternatively, you can click on the Comb Frequency field, type in a frequency in Hertz (from 175 to 11200 Hz), and hit Enter. To change the resonance amount, drag the handle up or down. Alternatively, you can click on the Resonance field, type in a resonance depth amount (from 0 for no resonance to 255 for maximum resonance), and hit Enter. Note: To change just one parameter and not the other, hold the Shift key to constrain your drag to just one dimension at a time. Tone Control When the Tone setting is positive, the Tone Control rolls off high frequencies. The larger the number, the greater the rolloff. When the Tone setting is negative, the Tone Control rolls off low frequencies, and the Comb Filter is bypassed. The larger the negative number, the greater the rolloff. Track Pitch
The Filter Page includes a Track Pitch button, whose effect is a little unusual:
When this button is turned on, the Comb Filter's peak frequency spacing will be based on the note's MIDI note number (pitch), with an optional offset in semitones. This can produce many interesting and unusual harmonic effects. The result is best heard when the Comb Filter resonance setting is fairly high.
For example:
If you set the semitone offset to 0, then the Comb Filter's peak frequencies will exactly match the pitch of the played note, and will adjust on a note-by-note basis. If you set the semitone offset to 7, then the Comb Filter's peak frequencies will always be 7 semitones (a perfect fifth) above the played note.

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