Let’s Get Visual
Figure 2 shows a simplified block diagram of a mixer with groups. The Group 1 mixing circuit accepts the signals from all the input modules you assigned to Group 1, and mixes them to the Group 1 output connector.
The Group 2 mixing circuit mixes all the Group 2 assignments to the Group 2 output connector, and so on.
Following each group mixing circuit is a group fader (Group 1 fader, Group 2 fader, etc.) Each group fader controls the level of each group independently.
The mixer’s master fader controls the level of all the groups at once, but only at the main output connectors.
If your mixer has eight groups, you might use them like this:
Group 1: Sanctuary PA speakers
Group 2: Vestibule PA speakers
Group 3: Stereo recording, left channel.
Group 4: Stereo recording, right channel,
Group 5: Assistive listening (hard of hearing) system.
Group 6: Internet streaming, left channel.
Group 7: Internet streaming, right channel.
Group 8: Not used.
Putting Reverb On The Choir – Only in The Recording
Let’s look at another situation. Suppose you want to record the choir during the service, and you also want to amplify it through the PA system. (Here I mean a traditional choir rather than a praise group singing pop music).
To prevent feedback, you will need to mic the choir closely – typically 1.5 feet in front of the front row, and 15 feet above the head height of the back row (Figure 3A).
This dose mic placement picks up very little of the room’s acoustical effects (reverberation). So the recorded choir will sound too dry – lacking a sense of space – unless you add some artificial reverb.
How do you record the choir with some reverb? In other words, how do you send the reverb only to the recorder, not to the PA loudspeakers? Here’s one way to do it:
1. First, connect the mixer’s AUX 1 output to the input of a digital reverb unit.
2. On the reverb unit, turn up the dry/wet MIX control all the way up to “Wet.” Turn the reverb unit’s level controls up about 2/3.
3. Connect mixer Groups 1 & 2 to the PA power amp inputs (or to the graphic EQ inputs). Connect Groups 3 & 4 to the recorder line inputs.
4. Assign all mics to Groups 1, 2, 3, and 4. Assign any audience mics only to Groups 3 and 4.