Peaking

The point at which a signal rises to its maximum instantaneous level, before falling

 

back down again. It can also describe an equaliser response curve affecting only

 

a band of frequencies, (like on a graphic equaliser), “peaking” at the centre of that

 

band.

Peak LED

A visual indication of the signal peaking just before the onset of clipping, which will

 

distort the signal.

PFL

Pre-fade listen: a function that allows the operator to monitor the pre-fade signal in

 

a channel independently of the main mix.

Phase

A term used to describe the relationship of two audio signals. In-phase signals

 

reinforce each other, out-of-phase signals result in cancellation. Phase is a meas-

 

urement of relative displacement between two waves of identical frequency.

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, nega-

 

tive to

 

negative. If this is reversed, the result will be out-of-phase signals (see ‘phase’

 

above).

Post-fade

The point in the signal path after a fader and therefore affected by the fader

 

position.

Pre-fade

The point in the signal path before a fader, 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.

Soundcraft EFX/EPM User Guide Issue 1210

43

Page 45
Image 45
Harman 1210KA Peaking, Band, Peak LED, Distort the signal, Channel independently of the main mix, Phase, Polarity, Tive to