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(sub) group | an output into which a group of signals can be mixed. |
headroom | the available signal range above the nominal level before clipping |
| occurs. |
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 |
| low impedance source. |
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 | a function that allows the operator to monitor the |
| a channel independently of the main mix. |
phase | a term used to describe the relationship of two audio signals. |
| |
| cancellation. |
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 |
| (see ‘phase’ above). |
the point in the signal path after the monitor or master fader and | |
| therefore affected by fader position. |
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. |
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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