About The Processing Structures - Orban OPTIMOD-FM 5500 Operation Manual

OPTIMOD-FM DIGITAL
also allows you to archive presets to your computer's hard drive (or other storage
device) and to restore them. However, archiving a preset is not the same as sav-
ing it. Archived presets reside on a storage medium supported by your computer,
while saved presets reside in the 5500's local non-volatile memory. You cannot
archive a preset until you have saved it. (See To back up user presets, system files,
and automation files onto your computer's hard drive on page 3-61.)
Note that if, for some reason, you wish to save an unmodified preset (ei-
ther Factory or User) under a new name, you must temporarily make an
arbitrary edit to that preset in order to make the S
pear. After you have saved the preset, reverse the edit and save the pre-
set again.

About the Processing Structures

If you want to create your own User Presets, the following detailed discussion of the
processing structures is important to understand. If you only use Factory Presets, or
if you only modify them with L
esting, but you do not need to understand it to get excellent sound from the 5500.
In the 5500, a processing structure is a program that operates as a complete audio
processing system. Only one processing structure can be active at a time. Just as
there are many possible ways of configuring a processing system using analog com-
ponents (like equalizers, compressors, limiters, and clippers), the 5500's DSP hard-
ware can realize several possible processing structures. Unlike an analog system,
where creating a complete processing system involves physically wiring its various
components together, the 5500 realizes its processing structures as a series of high-
speed mathematical computations made by Digital Signal Processing (DSP) inte-
grated circuit chips.
Not counting the stand-alone stereo encoder, there are three basic structures: Two-
Band, Five-Band, and Ultra-Low-Latency Five-Band. To select a structure, choose
a factory preset having the desired structure, and, if you wish, edit it to create a user
preset.
Two-Band is a purist, phase-linear structure. When correctly configured, it can be
used for protection limiting and we provide a preset that uses it for this. It is also the
basis for the CLASSICAL-2 BAND presets. It can have higher latency than the five-
band presets (up to 23 ms).
Five-Band is the basic structure used for popular music in its many variations. Be-
cause it provides effective automatic re-equalization of program material, it is also
used for news, talk, and sports.
The stereo enhancer, AGC, equalizer, and "back end" clippers are common to both
Two-Band and Five-Band processing and therefore stay the same when the 5500
switches between two-band and five-band operation. However, different controls
appear in the screens containing dynamics processing controls, as appropriate for
Two-Band or Five-Band multiband compression. The meters also change functional-
ity to display the Two-Band or Five-Band gain reduction.
, then you may still find the material inter-
-M
ESS ORE
button ap-
P
AVE RESET
3-15
OPERATION