SoundCraft Audio Mixing Console Model Spirit Studio - Manual (Page 7)

right meter. This allows the engineer to check the qual-
ity of the signal or to pin-point problems. Using PFL
will not affect the signals on the Left and Right Mix out-
puts.
Each input channel and the Group and Mix outputs
have an Insert ‘A’ gauge jack socket, which is a break
point in the signal path. It allows the signal to be taken
out of the mixer, through an external piece of equip-
ment and then back into the mixer directly after its
original exit point. The Insert point is normally by-
passed by the ‘A’ gauge jack socket contacts, and is
only brought into operation when a plug is inserted.
Typical uses would include Effects Processors, Limiters
or additional Equalisers.
The terms PRE and POST are often used in the context
of Inserts, Equalisers and Auxiliary Sends, and describe
whether that facility is placed before (Pre) or after (Post)
another particular section. This is explained further in
the detailed description of facilities.
A mixer is often judged, amongst other factors, by the
amount of Headroom available. This is a measure of
the reserve available to cope with sudden peaks in the
input signal, without distortion caused by Clipping,
when the signal becomes so high that it would exceed
the power supply rail voltages and is as a result limited.
This commonly occurs where gain settings are incor-
If the signal level is too low it may be masked
by the noise.
Signal Noise
If the signal level is too high, clipping distortion
may occur.
Clipped
Signal
Noise
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