SoundCraft Spirit SX, Руководство по смешиванию

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E. Using Signal Processors
The Difference between Signal Processors
and Effects
Unlike effects, which are creative in nature, signal
processors are used to control and manipulate sounds to
achieve the best audio quality performances and recordings.
Effects and signal processors should never be confused.
Whereas effects are “mixed” with an input to provide a
combined sound, signal processors alter an input, group or
mix signal completely. The signal is actually taken out of
the mixer entirely, “processed” and returned in its altered
state, in series with the original audio signal.
For this reason signal processors should be connected
using Insert Points and not the Auxiliary Send and Return
Loop (effects loop).
NB: Effects can be connected to inserts if necessary, but then the
proportion of the effect in the signal is governed solely by the
effects unit mix control.
The Different Types of Signal Processors
Broadly speaking, there are 5 different types of signal
processor in common use:
Graphic Equalisers
Graphic Equalisers work by splitting the sound spectrum
into narrow, adjacent frequency bands and giving each
band its own cut/boost slider. The term Graphic comes
about because the position or ‘curve’ of the sliders gives a
graphic representation of the way in which the settings
affect the audio frequency range.
Graphic Equalisers are most often used to process the
mix at live venues by notching out troublesome frequencies
that may be causing feedback. They may also be used to
enhance a mix at a poor sounding venue. In recording they
are used to create "flat" listening environments.
For more detail on venue acoustics go to section 4 - PA Mixing.
Parametric Equalisers
These are similar to the EQ found on an input channel but
may include more bands and additional bandwidth (Q)
controls which define how many frequencies in the band
are affected.
They are most often used to provide additional creative
control over an input signal when a mixer’s EQ is not
sufficient.
Gates
A gate is designed to shut down the audio signal path when
the input signal falls below a threshold set by the user. It
may be used to clean-up any signal that has pauses in it.
For example gates are widely used to prevent ‘spill’ between
adjacent mics on a multi-mic’d drum kit where, say, a tom-
tom mic may pick up the snare drum.
Expanders
Expanders accomplish much the same task as gates, though
they are more like compressors in reverse. Compressors
affect the gain of signals exceeding the threshold, while
expanders act on signals falling below the threshold. A gate
will close completely when the signal falls below its
SECTION 3: Mixing T
e
chniques
15
-3
-3
Lev
e
l
Time
Gate
Closed
Gate
Open
Gate
Closed
Threshold
FIG. 3.12
FIG.
3.14
FIG. 3.13
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