Muse Research MusePlayer manual v1.0 - Manual (Page 23)

A word about sound synthesis
F - PCM or "Sampling" synthesis
As digital technology became more afforable, digital audio
became more and more prevalent. This also helped create a
new class of synthesis employing the storage of digital
"snapshots" of sound using PCM (pulse code modulation), but
more commonly known as "sampling" synthesizers. A sam-
pling synthesizer captures a real sound by digitizing the
sound and storing it as a waveform, much like a camera stores
an image on a memory card. These waveforms are then used
as the oscillators in the synthesis engine and are processed
much the way an analog synthesizer would with envelopes
and filters.
Many sampling synthesizers store these waveforms in Read
Only Memory or ROM and then "reads" these samples back in
real -time, which is the main technology used in "sound
modules" like the E-mu Proteus. Sampling synthesis is argua-
bly the best way to recreate acoustic instruments such as
pianos and orchestral instruments, providing realism and high
definition, but at the cost of requiring large amounts of
memory to store the sample data. And since the harmonics of
an acoustic instruments vary greatly as they play through
their range, for best realism it is necessary to create a large
number of samples to make up a playable range in an instru-
ment (called Multi-sampling) thus further increasing the
memory requirements. That being said, samplers are used on
nearly every film and TV soundtrack and the technology
remains the premier technology in keyboards to produce
acoustic instruments that are big, expensive, or both. Examples
of famous samplers include The Fairlight CMI, E-mu Systems
Emulator, and Akai S series products. These hardware synthe-
sizers have since been replaced by software versions such as
Native Intruments Kontakt.
G - “Modeling” synthesis
There are two types of Modeling synthesis: analog modeling
that is used to create the sounds of analog oscillators but
using mathemetical routines to simulate the behavior (espe-
cially the non-linearities) of analog synthesizers, and physical
modelling that uses mathematical descriptions of the physical
properties of a particular element of an instrument, say a
string, a pipe, or a struck metal bar, and then using digital
signal processing to manipulate the behavior of the model
over time. Clavia Nordlead & Nordmodular are examples of
analog modeling synths, and physical modelling technology
has found the most success in virtual instrument form in pro-
ducts like Lounge Lizard and Pianoteq.
F - Miscellaneous
Phase distortion Synthesis
This is a synthesis method popularised by Casio synths back in
the 1980s, but is still found in some synthesizers today Phase
Distortion synthesis relies on reproducing the digital wave-
form in a non-linear way. Normally, when you play a digitized
waveform, the digital synth reproduces the data at the inten-
ded rate (eg 44.1kHz). A Phase Distorted system means part of
the data is read at one rate and the remainder at another rate
(eg first half at 22kHz and the second half at 66.2kHz [average
= 44.1kHz]). This varied data-reading changes the waveform.
In theory, you get a brand new waveform, and PD synthesis
gives timbres that sound similar to FM.
Tape Sampler (Chamberlain/Mellotron)
The forerunners of digital samplers, tape-based keyboards
used analog magnetic tapes to reproduce sounds that were
recorded on continuous loops stored in a large bin. These
devices, like the Chamberlain and the Mellotron basically had
a central captstan and a bunch of play heads. Pressing a key
pushed the head against the tape so you would hear the
sound. Each strip of tape had a finite length, so after a few
seconds (7 was typical) the sound would stop as the tape
quickly re-wound to the beginning. Made famous by the
Beatles and embraced enthusiastically by prog rock bands,
Mellotrons that aren't in museums are treasured by collectors
although digital sampling recreations are far more practical
and don't require maintenance!
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