Recording Consoles 773Clearly inputs 7 to 11 are all concerned with the drums. Once these channels have
been set so as to give a good balance between each drum, it is obviously convenient to
group these faders together so that the drums can be adjusted relative to the rest of the
instruments. This is the role of the separate summing amplifi ers in a live console, to
group various instruments together. That’s why these smaller “ mixers within mixers ”
are called groups. These group signals are themselves fed to the main stereo mixing
amplifi er, the master section. Mixer architecture signal fl ow is therefore channeled to
groups and groups to master output mixer, as shown in Figure 27.7. A block schematic of
a simplifi ed live-music mixer is given in Figure 27.8 in which this topology is evident.
27.5.4 Pan Control
Stereophonic reproduction from loudspeakers requires that stereo information is carried
by interchannel intensity differences alone, as there is no requirement for interchannel
delay differences. The pan control progressively attenuates one channel while
progressively strengthening the other as the knob is rotated, with the input being shared
equally between both channels when the knob is in its center (12 o’clock) position. In
the sound mixer shown in Figure 27.8 , note that the channel pan control operates in a
rather more fl exible manner, as a control that may be used to “ steer ” the input signal
between either of the pairs of buses selected by the routing switches. The fl exibility of
this approach becomes evident when a console is used in a multitrack recording session.
Table 27.2 Inputs to the mixer
Channel 1 Vocal mic
Channel 2 Bass amp mic
Channel 3 Lead guitar amp mic
Channel 4 Backing mic (for keyboardist)
Channel 5 Backing mic (for second guitarist)
Channel 6 Sax mic
Channel 7 Hi-hat mic
Channel 8 Snare mic
Channel 9 Bass drum mic
Channels 10 and 11 Drum overheads
Channels 12 and 13 Stereo line piano input
Channels 14 and 15 Sound module line input