Apple Logic Express 7 - Manual (Page 85)

Chapter 13 EFM 1 85
Modulator Wave
In classic FM synthesis, sine waves are use as Modulator and Carrier waveforms. To
extend its sonic capabilities, the EFM 1 Modulator provides a number of additional
digital waveforms.
When turned completely counter clockwise the Modulator produces a sine wave.
Turning the Wave parameter clockwise will step/fade through a series of complex
digital waveforms. These digital waveforms add a new level of harmonic richness to the
resulting FM sounds.
The Output Section
Sub Osc Level
For added bass response, the EFM 1 features a sine wave sub oscillator. This operates
one octave below the FM engine (as determined by the Transpose parameter). Turning
up the Sub Osc Level control mixes the sub oscillator sine wave with the EFM 1’s FM
engine output.
Vol(ume) Envelope
The Volume Envelope shapes the overall volume contour. The Volume Envelope consists
of four sliders: Attack time, Decay time, Sustain level, and Release time. The Volume
Envelope is triggered every time a MIDI note is received. The Attack slider defines the
time needed to reach the maximum volume level. The Decay slider sets the time
needed to reach the Sustain level (as determined by the Sustain slider). The Sustain
level is held until the MIDI note is released. The Release slider controls the time needed
to reach a volume level of zero, after the MIDI note has been released.
Stereo Detune
Stereo Detune adds a rich and diverse chorus-like effect to the sound of the EFM 1. This
is achieved by doubling the EFM 1 voice with a detuned second FM engine. The
amount of detune is adjusted using the Stereo Detune dial. A wide stereo effect is also
added, increasing the “space” and “width” of your sound.
Velocity
The EFM 1 is able to respond to MIDI velocity, and reacts with dynamic sound and
volume changes—harder playing will result in a brighter and louder sound. The
sensitivity of the EFM 1 in response to incoming velocity information is determined by
the Velocity parameter.
Set the Velocity control all the way to the left (counter-clockwise) if you don’t want the
EFM 1 to respond to velocity. Turning the control clockwise will increase velocity
sensitivity, and with it, dynamic changes to the sound that the EFM 1 is able to
produce.