Processors
in PA Systems
Processors are usually used to correct or control elements of the
sound.
Broadly, they are of two kinds:
• Equalisers.
These control the frequency content of a sound.
• Dynamic processors.
These control the dynamic range of a sound
(basically, how quiet it can be before it is silent, and how loud it can
possibly be).
This section includes
further information about:
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You won't find
a fully-featured professional PA system without one. |
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Not quite as
commonplace as the Graphic EQ, but they feature in the channel EQ section
of most higher-end desks, and their little "semi-parametric"
brother is found much further down the ladder (even some budget notepad
mixers have a single "semi-parametric" mid). |
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Controlling
dynamic range in a PA system is often important and necessary, but some
musicians won't have one in the building, let alone on their guitar,
voice, keyboard, drums, or - in short - any musical instrument they can
think of. |
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Limiters offer
some protection to loudspeakers, and can be useful anywhere that sudden
large signal peaks can appear (which can often happen accidentally, if
someone switches phantom power on with the mixer channel open, or drops a
sensitive microphone). |
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Expanders can
be used as noise gates without such a noticeable "chopping"
effect. |
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Noise gates can
be used as "auto-muting" on channels where no intended signal is
present, but can be difficult to use in live performance without unwanted
side-effects. |
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Crossovers are
another feature of all but the most basic sound systems. |
