Sonifex S2 - Glossary

S2 User Handbook
155
GLOSSARY
GLOSSARY
Glossary
Attenuation The reduction of a signal level. Attenuation is usually measured in dB.
AES Audio Engineering Society.
AES/EBU Professional digital audio standard covering frame format, connections
and interfaces. Interface is usually on XLR sockets and plugs.
Balance The relative levels of the left and right channels
of a stereo signal.
Cleanfeed A cleanfeed is the signal produced by the telco module, which is used
as the output to be fed back to a caller on a telephone line. A true
cleanfeed is the sum of all the other signals, which constitute the
programme output, except for the caller’s audio.
Clipping The onset of severe distortion in the signal path, usually
caused by the peak signal voltage being limited by the circuit’s
headroom.
CMRR Common Mode Rejection Ratio. This is the ratio of the extent to which
a dierential amplier will cancel noise, which is present on both
inputs, compared to its ability to amplify the wanted signal.
Cross-talk This is the amount of an unwanted signal which appears,
or is induced, on a dierent or unassimilated signal. The problem is
usually most prevalent with adjacent channels.
CUE See PFL.
dB (decibel) A ratio of two voltages or signal levels, expressed by the equation
dB=20LOG(V1/V2)
Adding the sux “u” denotes that the signal is relative to 0.775V RMS.
Adding the sux “v” denotes that the signal is relative to 1V RMS.
De-emphasis Pre-emphasis and de-emphasis are techniques used to improve
the overall signal to noise ratio in communication channels.
The frequency response of the channel is weighted with a 6 dB per
octave slope prior to transmission (pre-emphasis), and then the
inverse of this weighting is applied at the receiving end (de-emphasis)
to restore a at frequency response.
EIN Equivalent Input Noise. It is the ratio of output noise to the gain. It
describes the level of noise which would need to be fed into an ideal
amplier to produce the measured output noise.
EQ EQualisation. This is the method of cutting or boosting selected bands
of frequencies in the signal.