SoundCraft Spirit Monitor - Manual (Page 7)

The Wedge output refers to the engineer’s own monitoring
output, which will typically feed a floor-mounted ‘wedge-
shaped’ speaker via a suitable power amplifier.
The Talkback system allows the monitor engineer to talk back
to artists, either individually via selected monitor outputs, or
together using a switch on the master section.
Creating monitor mixes on stage in close proximity to micro-
phones demands constant awareness of the problem of
acoustic feedback. The Dim buttons enable the engineer to in-
stantly lower the output level on any outputs to avoid this
problem while more precise level adjustments are made.
A mixer is often judged, amongst other factors, by the amount
of Headroom available. This is a measure of the reserve avail-
able 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 set-
tings are incorrectly set or where sources are improperly
matched to the mixer input. If the source signal is too high,
clipping and distortion results. If the signal is too low it be-
comes masked by the background noise which is present to
some degree in all mixers. The diagram below illustrates this
point.
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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