Behringer MX9000 user manual Main equalizer, Aux sends

3.4 Main equalizer

Fig. 3.3: Main equalizer

The main equalizer can be switched (S10) out of circuit for easy A/B comparisons between EQed and straight signals, or for when you know you don’t want to use desk EQ at all. It is best considered in three sections. First off there are two Baxendall shelving frequency controls for treble and bass, at 12 kHz and 80 Hz respectively (P4 and P9). These are DUPLICATED for the B-channel (P18 and P19), not merely “SPLIT” off from the main EQ. I.e. you can have a full 4-band EQ on the main channel AND a 2-band EQ on B-channel.

Secondly, there are two semi-parametric swept mids, Q fixed at 1, which cover the bands 300 Hz to 20 kHz and 50 Hz to 3 kHz. An unusually broad frequency range is catered for, and there is an enormous 3-plus octave overlap between the two mid bands (P5, P6, P7 and P8). No experienced engineer will complain about that! All four bands offer 15 dB of cut and boost.

Thirdly there is a steep high pass (lo cut) filter (S11), slope @ 12 dB/octave, -3 dB @ 75 Hz, for reducing floor rumble, plosives, woolly bottom end, etc.

3.5 Aux sends

All six aux sends are mono and post EQ. They are switchable PRE/POST fader in two banks (S13 and S16). For aux sends 1 and 2, two dedicated pots (P12 and P13) are used. These can be taken from a point before or after the channel fader, i.e. PRE or POST (S13). Aux sends 3 and 4, and 5 and 6 are serviced by two potentiometers (P14 and P15). The SHIFT button (S15) determines whether buses 3 and 4 or 5 and 6 are addressed. Also, these four sends can be derived from the main mix or MIX-B, depending on SOURCE (S17), and, as before, can be pre or post (S16).

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