Muse Research MusePlayer manual v1.0 - Manual (Page 22)

A word about sound synthesis
English 22
B - Frequency Modulation (FM) synthesis
Invented at Stanford University, FM synthesis produces an
output signal by oscillating the frequency of a source oscilla-
tor's signal at such a high frequency that it starts to "modula-
te" and produce new tones in the process. This process can
generate fairly complex waveforms containing multiple fre-
quencies/sidebands with only two oscillators, requiring mini-
mal computations. FM Synthsis is particularly good at crea-
ting synthesized version of vibrating bars, hence its popularity
as a sound for use in Electric Pianos. The YAMAHA DX7 is the
best example of a popular FM synth.
C - Wavetable synthesis
This is a synthesis technique where the waveform of the
oscillator is stored as a table of values in a digital manner, and
then "read back" and processed in real-time by the synthesis
engine. As a result, quite complex and harmonically rich
waveforms can be stored in the synthesizer for combining
with subtractive synthesis techniques to make very expressive
sounds. One common addition to wavetable synthesis is that
each instrument waveform contains a loop region. This region
starts after the attack segment of the digital audio has played
and repeats while the instrument's note is sustained (i.e. while
a note is held). Then the release segment of digital audio
finishes off the note. Wavetable synthesis is a more limited
form of the more generalized Sampling synthesis, explained
later.
D -”Vector” synthesis
Vector synthesis was pioneered by the SCI Prophet VS and
made popular by the Korg Wavestation family. Vector
Synthesis was loosely based on substractive synthesis but
with the example of german PPG in mind, they created an
instrument able to crossfade waveforms in real time on a two
dimensional pattern in real-time with a joystick. The user had
access to 128 different digitally stored waveforms, 4 wave-
forms ("voices") could be mixed in real time. Then the result
went through a classical analog path with two LFOs per voice,
VCF, VCAs and enveloppes (loopable envelopes to create
really interesting soundscapes). The resulting sound had the
life and motion of rich and complex digital textures combined
with the warmth of analog filters and amps to finalize the
picture.
E - Additive synthesis
Additive synthesis can be found in different instruments, the
first one being the famous tonewheel organ and its equally
famous drawbars used to add or withdraw harmonics from
the overall sound. A rotating shaft with electromagnetic pic-
kups created different harmonics that were added together in
varying proportion using the organ "stops" to create the desi-
red timbre.
The idea of Additive Synthesis is to build a complex waveform
from its basic elements. It works by mixing (summing) one or
more simple waveforms, such as sine waves at different fre-
quencies together to create a more complex waveform.
Theoretically, it is possible create any sound by adding enou-
gh sine waves of different frequencies together using some-
ting called the Fourier series. In real life however, sounds
evolve and change in subtle ways making the creation of
complex sounds using simple elements a huge technological
challenge. However, Additive Synthesis has made an impact
on the world of synthesis as the computations necessary
tomake complex sounds have become less burdensome
thanks to faster CPUs. Perhaps the most famous Additive
Synths came from Kawai in their K series and the PPG
Waveterm.