Working with the EFM1 Modulation Parameters
FM synthesis is, at its core, caused by the intensity and type of modulations that take place in the signal path. Therefore, the “modulators” outlined in this section have a different impact (and role to play) than equivalent envelopes and LFOs found in analog synthesizer designs.
- Modulation Env(elope) sliders: Controls both the FM (Intensity) and Modulator pitch parameters over time. The envelope is triggered every time a MIDI note is received.
- Attack slider: Sets the time it takes to reach the maximum envelope level.
- Decay slider: Sets the time it takes to reach the Sustain level.
- Sustain slider: Sets a level that is held until the MIDI note is released.
- Release slider: Sets the time it takes to reach a level of zero, after the MIDI note has been released.
- Modulator Pitch knob: Determines the impact of the modulation envelope on the pitch of the modulator oscillator.
Turn the knob clockwise to increase the effect of the modulation envelope. Turn the knob counter-clockwise to invert the effect of the modulation envelope: the envelope slopes down during the attack phase, and slopes up during the decay and release time phases.
At the center (0) position, the envelope has no effect on the pitch of the Modulator oscillator. Click the “0” to center the Modulator Pitch knob.
- FM Depth knob: Determines the impact of the modulation envelope on FM intensity.
Turn the knob clockwise to increase the effect of the modulation envelope. Turn the knob counter-clockwise to invert the effect of the modulation envelope: the envelope slopes down during the attack phase, and slopes up during the decay and release time phases.
At the center (0) position, the envelope has no effect on FM intensity. Click the “0” to center the FM Depth knob.
- LFO (Low Frequency Oscillator) knob: Determines the amount of modulation applied to FM intensity or pitch.
Turn the LFO knob clockwise to increase the effect of the LFO on FM Intensity. Turn it counter-clockwise to introduce a vibrato.
At the center (0) position the LFO has no effect. Click the “0” to center the LFO knob.