Sound PA Desk / Mixer
Everyone wants to be able to sit behind the mixer, knowing which knob to turn or button to press when it looks so complicated to others. Fortunately sound desks aren't actually that complicated.
The Channel
A mixer is mostly channels which are nearly identical, the bigger the board mostly means more channels. Small mixers don't have so many options per channel but even then the additional buttons are often more like fine-tuning.
Each channel starts at the top, where the gain/sensitivity is set. It is not the volume control as some like to think of it, more like the 'incoming level' and how much a particular microphone will pick up.
Next comes the equalisers where you can set whether it has more top-end (high frequency), middle (sometimes hi-mid and low-mid) and bass (low frequency). In some cases you can choose to not use these options.
Then you have the auxillary/foldback/submixes which are the amounts that a particular channel is in a certain mix (looking across them left-to-right you'll see a full mix). For example the lead guitar might be in 3-4 monitors.
Finally comes Pan (useful mostly for stereo applications, like left and right from a piano but usually just left in the middle) and the ubiquitous slider. This slider again isn't really a volume control, the ideally setting being 0, rather it's how much you increase or decrease it from there.
Sub Masters and Masters
Smaller mixers have just one master slider, often in a different colour and either on the right or in the middle of two main sets of normal sliders. In a larger mixer you can have sub masters which help to divide the inputs.
For example you might put the instruments onto 1 and 2, and the voices onto 3 and 4. This can be done by some buttons next to the channel slider. Then you can bring the instruments up and down collectively separate of the voices.
In some cases you might see a 'C' which stands for 'Centre' or 'Mix' on the individual channels meaning you can send some channels directly to the general output or even some mix thereof.
All the other stuff
There are a lot of other buttons in the middle, most of which you won't need other than perhaps to bring in a stereo channel from a DVD player but even that can be done down a normal channel or two.
Things like 'Phantom Power' and 'Low Cut' can mostly be ignored. If you're stuck then get your channel to look similar to a working channel. Start with the simple things, like setting the Gain and getting used to using the equalisers.
