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Chapter 22 ES2 235
Oscillator 1’s frequency modulated sine wave, modulated by Oscillator 2 set to sine
wave. Oscillator 2 was set to three times the frequency of Oscillator 1 ( + 19 semitones).
The modulation intensity is low (Wave control at about 12 o’clock). As the wavelength
(the duration period) of the modulating Oscillator is a third of that of the modulated
Oscillator, the sine is accelerated and slowed down three times within a phase.
Oscillator 1’s frequency modulated sine wave, modulated by Oscillator 2 set to sine
wave. Oscillator 2 was set to three times the frequency of Oscillator 1 ( + 19 semitones).
The modulation intensity is much higher (Wave control at about 3 o’clock). The
distortion of the basic sine wave is much stronger, resulting in more harmonics
becoming audible.
The effect of frequency modulation depends on both the modulation intensity and
frequency ratio of both Oscillators.
The upper graphic shows a slightly deformed sine wave of Oscillator 1, modulated in
frequency by Oscillator 2 at double the speed of the carrier (Oscillator 1). The resulting
waveform resembles a rectangular wave or clipped sine wave.
The upper graphic shows a slightly frequency modulated sine as the output signal of
Oscillator 1, with the modulator frequency being identical to the carrier frequency. The
resulting waveform resembles a lowpass filtered sawtooth wave.
The resulting spectrum not only depends on the frequency modulation intensity and
frequency ratio, but also on the waveform used by the modulating oscillator (Oscillator
2). The modulation that takes place varies according to the waveform selection for
Oscillator 2—it might even be an oscillation that is synchronized to Oscillator 1! Given
the 100 available Digiwaves, countless combinations of modulation intensities and
frequency ratios, the frequency modulation of the two oscillators delivers an infinite
pool of spectra and tone colors.