soundcraft spirit live 4.pdf - Free Pro Audio Schematics

INPUT7. HI- PA SS FILTERPressing this switch inserts a 12dB per octave 100Hz Hi-PassFilter in the signal path, immediately after the input amplifier.This is particularly useful on live vocals, and its use isstrongly recommended, even on male vocals. It can also beused for filtering out low frequency hum.Frequency Response Curves of the Hi-Pass FilterdB HI-Pass Filter4.03.02.01.00.0-1.0-2.0-3.0-4.020 100 1k 10k 20kFrequency/Hz8. EQ UA LISERThe Equaliser(EQ) comprises three sections. The uppercontrol provides H.F.(treble) boost and cut of +/ -15dB. Thelower two pairs of knobs are arranged as a cut/ boost control(lower knob) of +/ - 15dB, and a SWEEP(frequency) controlwhich determines at which frequency the boost/ cut actionwill be centered. The LF sections are essentially Swept LowFrequency controls, covering a range from 40 to 400Hz andproviding much greater flexibility than a conventionalLF(bass) control. The MID section, with a frequency rangefrom 250Hz to 8kHz is particularly versatile for vocals,enabling particular characteristics of the singer to be lifted orsuppressed very precisely.Frequency Response Curves of the EqualiserdB LF Section20.015.010.05.00.0-5.0-10.0-15.0-20.020 1001k 10k 20kFrequency/HzPa g e 12