User Manual

32 Filter Dave Smith Instruments
3. Return the cutoff knob to its halfway position, hold down a note again
then turn the resonance knob about halfway up. Notice how the sound
changes as a band of frequencies near the cutoff is amplied.
4. Rotate the lter’s cutoff knob again and listen to a classic resonant
lter sweep.
In the previous example, you controlled the lter cutoff by hand. In most
cases, you will use the Filter Envelope to do this. To learn more about the
Filter Envelope see page 37.
Filter Parameters (Front Panel)
Drive: 0...127—Increases signal input to the lter, boosting volume and
adding harmonic saturation and warmth.
Sampled instruments have a Boost parameter (in the inst misc tab) that is useful
for increasing signal level to the lter if necessary. This can enhance lter Drive.
Cutoff: 0...164—Sets the lter’s cutoff frequency. Frequencies are
reduced from the top down, cutting the high frequencies and passing the
low frequencies, hence the name “low-pass.”
Resonance: 0...255—Emphasizes a narrow band of frequencies around
the cutoff frequency. High levels of resonance can cause the lter to self-
oscillate and generate its own pitch.
High levels of resonance can sometimes cause the Prophet X outputs to clip.
Monitor your outputs carefully to ensure optimal, clean signal levels.
Key Track: 0...127—Sets the amount of modulation from the keyboard
to the lter’s cutoff frequency. Any setting above zero means that the
higher the note played on the keyboard, the more the lter opens. This
is useful for adding brightness to a sound as higher notes are played, which
is typically how acoustic instruments behave. When set to zero, keyboard
lter tracking is off, meaning that lter frequency is unaffected by playing
higher or lower notes on the keyboard. When set to 127, the lter will track
in half-step increments, which can be useful if you are using the lter to
generate a pitch through self-oscillation.