Apple Logic Express 7 - Manual (Page 83)

Chapter 13 EFM 1 83
Modulation Env(elope)
To control the FM (Intensity) parameter dynamically, the EFM 1 provides a dedicated
ADSR (FM) Modulation Envelope, consisting of four sliders: A (Attack time), D (Decay
time), S (Sustain level) and R (Release time). The envelope is triggered every time a MIDI
note is received. The Attack slider sets the time needed to reach the maximum
envelope level. The Decay slider sets the time needed to reach the Sustain level
(determined by the Sustain slider). The Sustain level is held until the MIDI note is
released. The Release slider sets the time needed to reach a level of zero, after the MIDI
note has been released.
FM Depth
The strength, or impact, of the Modulation Envelope on the FM intensity is determined
by the FM Depth control.
Turning the FM Depth control clockwise increases the effect of the Modulation
Envelope. Turning the FM Depth control counter clockwise inverts the effect of the
Modulation Envelope, meaning that the envelope slopes down during the Attack
phase, and slopes up during the Decay and Release time phases.
In the center (0) position, the envelope does not have an effect. You can easily center
the FM Depth dial by clicking on the 0.
Modulator Pitch
The impact of the Modulation Envelope on the pitch of the Modulator oscillator is
determined by the Modulator Pitch control.
Turning the Modulator Pitch control clockwise increases the effect of the Modulation
Envelope. Turning the Modulator Pitch control counter-clockwise inverts the effect of
the Modulation Envelope, meaning that the envelope slopes down during the Attack
phase, and slopes up during the Decay and Release time phases.
In the center (0) position, the envelope does not have an effect. You can easily center
the Modulator Pitch dial by clicking on the 0 button.
LFO
The LFO (Low Frequency Oscillator) serves as a cyclic modulation source for FM
Intensity or Vibrato. Turning the LFO control clockwise increases the effect of the LFO
on FM Intensity. Turning it counter clockwise introduces a vibrato.
In the center (0) position the LFO does not have an effect. You can easily center the LFO
dial by clicking on the 0.
Rate
The speed/rate of the LFO cycles is set with the Rate parameter.