16 . The equalizer . One of the unique sections in any mixer is the equalizer section (# 16 ). A small mixer might only provide access to a boost and cut for two fixed EQ bands — typically around 100 Hz and 10 kHz or so . Other mixers offer four bands of fully parametric EQ along with separate high- and low-pass filters . The EQ section of the channel strip in this illustration has fixedfrequency boost and cut on the high and low bands along with a sweepable semi-parametric mid-frequency band .
17 . Connection splitter . The output of the EQ section — and before the fader — splits (# 17 ), with one side headed to the aux section and the other heading the pre fader listen button .
18 . The PFL button . The Pre Fader Listen ( PFL ) button (# 18 ) is fed from the split just after the EQ section . When PFL is selected , the pre fader signal is routed to a monitor bus — typically a headphone output in a live application , or to the reference monitors in a studio application . Some mixers take a split of the send after the fader , too , which is routed to an After Fader Listen ( AFL ) button .
19 . Pre- and post-fader switches . Notice that the pre- and post-fader switches are simple splits off of the signal path just before the signal is routed to the fader and just after the signal leaves the fader preamp .
20 . Auxes 1 and 2 . The pre- and post-fader switches feed the auxchannel potentiometers (# 20 ), which control the send levels to the aux bus outputs . On an analog console , the aux buses are routed to physical outputs on the back of the board . On a digital console , the auxes might also be routed to physical outputs , but they can also be routed internally to feed plug-ins or other internal buses . When it ’ s in the up position , the Pre / Post button on the channel strip sends a pre fader signal to the aux bus . When it ’ s in the down position , the Pre / Post button on the channel strip sends a post fader signal to the aux bus .
21 . Channel fader and preamp . The channel fader (# 21 ) controls the preamp send level to the group and main console outputs . This channel diagram reveals plainly how the post fader signal is routed and how the signal splits and feeds the assign buttons . Some mixers also route the signal directly to the main FOH mix . A simple review of the mixer ’ s manual and block diagram would quickly solve any question about the way the mixer routes the signal .
22 . Pan potentiometer . The preamplified signal feeds the left-right pan pot , which also pans the signal between the odd and even eight-channel bus or subgroup assignment buttons . When assigning buses , often the signal is sent to either a left ( odd ) or right ( even ) numbered bus . Some recording mixers provide a Direct button that bypasses the pan pot and routes the incoming signal directly to the recorder track with the same number as the mixer channel . In a live application , the assigns are used to feed mono or stereo mains , aux ,