Mixing desks can vary at size, you will find small desks and massive desks! They are generally referred to by the number of input and output channels they have.
An input channel is a place where a single audio signal can be connected into the soundboard. An output channel is a path of exit from a soundboard for an audio signal.
When most of us look at mixing desks, whether walking past them at shows, or looking at them from backstage tours, most people wouldn’t know where to start, but it’s actually more easier than you think. There is a lot to see and a lot to learn. But it’s not impossible.
Here is is 2 photos below of 2 mixing desks I’ve recently worked with at local gigs.
Every normal mixing desk will contain a XLR Input, Equalization (high,mid,low), reverb, gain sliders, master gain, mute, solo,level meters and the output.
Each channel on a mixer typically has what are referred to as auxiliary sends (aux) it’s common to find 1-8 aux sends on a sound desk. Each AUX send typically has a knob associated with that particular aux send on each verticle channel strip.
Generally each channel has some sort of equalization (EQ) that is controls to adjust the tone quality of the sound. Small mixers only have space for bass and treble, and other sound desks maybe have bass, treble, mid range and adjustable range controls. The adjustable controls are called parametric equalizers which allows the sound technician to choose not only to boost or cut a frequency range but to choose which range to work with. For an example, removing the bass from a wireless mic input can reduce the annoying clunky thuds we can sometimes hear with a mic.
You next have the sliders/faders. They are usually located at the bottom of the mixing desk, which are controlling the level of the signal sent to the outputs of the mixing desk.
Another 2 buttons commonly found on mixing desks are “solo” and “mute”. Mute, which is obvious, silences the input signal. This will usually be used when musicians are offstage, or not using the mic for another reason. If the mic sets are wireless and attached to the person, the sound technician will usually mute them while backstage, otherwise conversations backstage would be broadcast out to the crowd!
The solo switch found in many different forms on sound mixers allows a signal to be listened to by itself. Often it can be routed to a pair of headphones which is a really useful feature for tapes/CDs.
Equalizers are used to shape the tone of a sound, with mic’s the equalizers can be extremely useful in eliminating feedback problems, yep, that awful hum or high pitched squeal that makes everyone pull a face! Equalizers are also often used to overcome deficiencies in the speakers used or the venue they are being used in.
Below are a few photos of the Bon Jovi mixing desk! :)