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highpass filter a filter that rejects low frequencies.
impedance balancing a technique used on unbalanced outputs to minimise the effect of
hum and interference when connecting to external balanced inputs.
insert a break point in the signal path to allow the connection of external
devices, for instance signal processors or to another mixer.line level
signals at a nominal level of -10 to +6dBu, usually coming from a
low impedance source.
mute groups a method of combining the on/off status of a selection of channels
under a single control button.
pan (pot) abbreviation of panorama: controls levels sent to left and right out-
puts.
peaking an equaliser response curve affecting only a band of frequencies i.e.
based on a bandpass response.
PFL (pre-fade listen) a function that allows the operator to monitor the pre-fade signal in
a channel independently of the main mix.
polarity a term used to describe the orientation of the positive and negative
poles of an audio connection. Normally connections are made with
positive to positive, negative to negative and this would correct
polarity. If this is reversed, the result will be out-of-phase signals
(see phase above).
post-fade the point in the signal path after the monitor or master fader and
therefore affected by fader position.
pre-fade the point in the signal path before the monitor or master fader posi-
tion and therefore unaffected by the fader position.
rolloff a fall in gain at the extremes of the frequency response.
shelving an equaliser response affecting all frequencies above or below the
break frequency i.e. a highpass or lowpass derived response.
spill acoustic interference from other sources.
stereo return an input specifically designed to receive the output of effects or
other external processing devices
talkback the operator speaking to the artistes or to tape via the auxiliary or
group outputs.
transient a momentary rise in the signal level.
unbalanced a method of audio connection which uses a single wire and the
cable screen as the signal return. This method does not provide the
noise immunity of a balanced input (see above)
+48V the phantom power supply, available at the channel mic inputs, for
condenser microphones and active DI boxes.
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