Edirol SD-80 - Manual (Page 18)

18
Using the internal sound generator
About parts and sounds
The SD-80 is able to produce 32 different sounds at once. A sound generator such as the SD-80 that is able
to produce many different sounds simultaneously is called a “
multitimbral sound module .” “Timbre”
refers to the unique characteristics that result in the sound of one instrument being different from that of
another. The ability to simultaneously produce 32 different instrument sounds means that, using the
analogy of an orchestra, you can produce an ensemble consisting of 32 different instrumental parts. On
the SD-80, the sound produced by each part is called an
Instrument ( "Instrument list (GM2 / Native
mode)" (p. 95)). You can assign a desired instrument to each of the 32 parts, creating a 32-part ensemble.
■ Different types of part
The SD-80 has 32 parts , which are divided into groups A and B. Each group is numbered from 01–16; i.e.,
A01–A16 and B01–B16.
Each part can be set either as an
Inst part or a Drum part . Inst parts are used to play melody, bass, etc.
Drum parts are used to play percussion-type sounds. This setting is called the Part Mode .
By default, the following part mode is selected for each part.
■ Polyphony and voices
Each of the SD-80’s sounds consist of units called “ voices .” There is a limit to the number of voices that
can be used, and the SD-80 is able to use 128 voices simultaneously. Some sounds (instruments) use
more than one voice ( "Instrument list (GM2 / Native mode)" (p. 95)). The main reason that an instrument
uses some voices is so that velocity can be used to shift between different sounds, or so that multiple
sounds can be layered to create a richer tone.
When you attempt to play more than 128 voices on the SD-80, the most-recently played note will be given
priority, and the oldest of the currently-sounding notes will be turned off one by one. If you are using
only instruments that consist of only one voice, you will be able to play 128 notes simultaneously.
However, if you use instruments that consist of two or four voices, fewer than 128 notes can be played
simultaneously. Even if a MIDI note-off message is received, a voice will continue to be used as long as
that note continues to sound. You need to remain aware of this, particularly when using sounds that have
a long release time.
Part mode Corresponding parts
Inst part A01–09, A11–16, B01–09, B11–16
Drum part A10, B10