In addition to the main L/R outputs, a four-bus console has four additional outputs that correspond to faders that control the signal routed to them.
The faders are typically labeled “bus 1,2,3,4” or “Sub out 1,2,3,4” etc.
Each channel has a switch, which allows you to assign its signal to a particular bus.
With this configuration, we could run a stereo monitor mix.
If we decided to do this, we would assign each channel to buses 1 and 2.
The output of bus 1 will be routed through the snake’s return 3, and the output of bus 2 output will be routed through return 4.
Remember we’re using returns 1 and 2 for the main house mix. Return 3 will be routed to the amp that powers the left side of the monitor mix and return 4 to the right side.
I only recommend doing a stereo monitor mix if in-ear monitors are to be used. Most applications require the use of on stage loudspeakers (monitors or wedges).
For this reason, it is a good idea to run a mono monitor mix. Monitors on stage would normally be too complex to run a stereo monitor mix. By assigning all of the instruments to bus 1, we can be sure that all of the stage speakers represent an overall mix for all of the musicians on stage.
Because we are only using bus 1 for this mix, we could then use bus 2 for some accent monitors on stage.
For example, if all of the musicians can hear the overall mix, we could assign only the vocals and other lead instruments to bus 2 and route that bus to spot monitors for singers (who like to hear themselves heavily in the monitor mix) as well as other lead instrumentalists who cue off of each other.
If we had more returns in our snake we could even provide accent monitors for the bassist and drummer/percussionist, for example, by using buses 3 and 4.
One limitation of using buses for your monitor mix is that if you assign a particular channel to a bus, you might not be able to route that signal to another bus or at least not the bus you need.
Another limitation is that on some consoles, you cannot adjust the amount of signal that each channel contributes to each bus. That means that whenever the bus is assigned, the entire signal from that channel is routed to that bus assignment.
The amount of individual signal from each channel to the bus is determined by the position of the channel fader.
Many manufacturers design features that allow for more possibilities; however, that usually means more circuitry, hardware and board space for additional faders or pots.
More features means more expensive. This is a quick and easy way to run monitors, but there are other avenues that lead out of the console – the auxiliary send outputs (aux sends).
