SoundCraft Rac Pac manual GloSSARY, AFL After Fade Listen

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GloSSARY

AFL (After Fade Listen)

a function that allows the operator to monitor the post-fade signal in a channel independently of the

 

main mix.

Balance

the relative levels of the left and right channels of a stereo signal.

Balanced

a method of audio connection which ‘balances’ the signal between two wires and a screen which carries

 

no signal. Any interference is picked up equally by the two wires, but out of phase resulting in

 

cancellation of the interference signal.

Clipping

the onset of severe distortion in the signal path, usually caused by the peak signal voltage being limited

 

by the circuit’s power supply voltage.

dB (decibel)

a ratio of two voltages or signal levels, expressed by the equation dB=20Log10 (V1/V2).

 

Adding the suffix ’u’ denotes the ratio is relative to 0.775V RMS.

DI

(direct injection) the practice of connecting an electric musical instrument directly to the input of the

 

mixing console, rather than to an amplifier and loudspeaker which is covered by a microphone feeding

 

the console.

Effects

the use of devices to alter or process the sound to add special effects e.g. reverb, normally as a mix of

 

the original (‘dry’) sound and the treated version.

Equaliser

a device that allows the boosting or cutting of selected bands of frequencies in the signal path.

Feedback

the ‘howling’ sound caused by bringing a microphone too close to a loudspeaker driven from

 

its amplified signal.

Foldback

a feed sent back to the artistes via loudspeakers or headphones to enable them to monitor the

 

sounds they are producing.

Frequency response

the variation in gain of a device with frequency.

Ground Compensation

a technique used on unbalanced outputs to cancel out the effect of ground loops caused by connections

 

to external equipment.

Headroom

the available signal range above the nominal level before clipping occurs.

High Pass filter

a filter that rejects low frequencies.

Line level signals

at a nominal level of -10 to +6dBu, usually coming from a low impedance source.

Oscillator

a built-in tone generator for test and line-up purposes.

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.

Phantom Power

the +48V d.c. voltage applied equally to the two signal pins of a balanced mic input to provide

 

powering for condenser microphones.

Post-Fade

the point in the signal path after the channel or master fader and therefore affected by fader position.

Processor

a device which affects the whole of the signal passing through it, e.g. gate, compressor or equaliser

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.

Signal to Noise Ratio

a expression of the difference in level between the audio signal and background system noise.

Solo-in-Place

a function that allows the operator to listen to a selected channel on its own but complete with all relevant

 

effects, by automatically muting all other inputs.

Spill

acoustic interference from other sources.

Sweep EQ

an Equaliser section ( e.g. MID EQ) which operates at a variable rather than fixed frequency giving

 

increased flexibility to the user.

Talkback

the operator speaking to the artistes or to tape via the auxiliary or group outputs.

Tape Return

a line level input provided specifically to receive the playback output of a tape machine

Transient

a momentary rise in the signal level.

TRS Jacks

a 3-pole jack with Tip, Ring and Sleeve connections

Unbalanced

a methode of audio connection which uses a single signal wire and the cable screen as the signal return.

 

This method does not provide the noise immunity of a balanced input (see above).

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SPIRIT FOLIO RAC PAC

 

 

 

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Contents MIX Safety Precautions IntroductionConnectORS ConNections Input Channels Connections Master Section Initial Setting UP Stereo Recording to DAT Setting UP for RecordingTrack Recording Controls in Detail Mono Input Channels TrimEqualiser AUX SendsFader PANRouting SoloStereo Input CHANNELs EqualisationBalance Auxiliary Sends Stereo ReturnsLevel PFLMIX Track 2TK Return Level Groups to MIXMIX Fader 2TK to MIXSpirit Folio RAC PAC Auxiliary Masters Solo ModePhantom Power AUX AFLApplications Multitrack RecordingStereo Public Address Relocating the connector panel Technical Specification GloSSARY AFL After Fade ListenSystem Block Diagram