Mixing 101

Mixing 101

A guide to mixing using the Yamaha MG10XU

The heart of the live sound system is the mixer. The mixer’s basic function is to mix the live sources from the stage to produce a good balance for everyone in the audience to hear. A simple analogue mixing console provides basic control over the sound sources, allows the operator to mix them together and control the overall output level of the mix.

Controlling the signal flow

The input levels are adjusted and balanced between channels using the “gain” controls, which also have a “pad” switch to reduce very high input signals if necessary. The EQ section adjusts the sound by boosting or cutting different frequency bands to remove unwanted characteristics, or to gently enhance the low, middle or high frequency content. There is also a high-pass filter on the mono channels, which can further reduce low frequencies.

The main output mix will be a stereo signal, and the “pan” controls are used to place each input source anywhere between extreme left and extreme right. If the pan control stays in its centre position, then the voice or instrument on that channel will be fed equally to left and right and will appear to be placed centrally in the stereo spread. The channel fader is the last control on each channel, and is used to control how much of the channel signal is sent to the main mix. On small mixers like the MG10XU this will be a rotary control, which acts in exactly the same way as the up/down faders on larger consoles.

Auxiliary mixes

Sometimes a second mix output will be required. For example, to feed into a monitor system or an external effects processor such as a reverb unit. Such additional mixes are called auxiliary mixes, and each channel has an “aux send” control which acts exactly like the channel fader, but in this case ends the signal to an auxiliary mix bus instead of the main output. Signals to the auxiliary mix buses can be sent from each channel from a point before or after the channel main mix output fader, and are accordingly called pre-fade or post-fade sends. Pre-fade sends are not affected by the position of the channel fader and are generally used for stage monitors. Whereas post-fade sends follow the fader setting and are used for sending to effects units.

Integrated effects

Some modern mixers such as the MGXU series mixers incorporate built-in digital effects. The MG12XU provides two aux sends (one for internal FX). In addition, the MG12XU is equipped with two group buses, used to control the overall level of selected channels.

Master section

The right-hand part of the console is called the master section, and this is where we find the output level controls for the main mix, aux mixes and effects parameters. All of the associated output connectors are usually found in this section, together with the main level meters and headphone socket.

Putting theory into practice

Always try to give yourself plenty of time to set up the sound system, particularly if you are working in a new or unfamiliar venue. It is much easier to set up when you have the space to yourself but this will not always be the case, so a careful and methodical approach will pay dividends whatever the circumstances. Preparing for a gig is an essential part of the whole process and can save time and prevent disasters happening later. If you spend some time familiarising yourself with your mixer, as well as the other parts of the sound system, you will be able to mix any gig with confidence.

Anatomy of a Mixer

This MG10XU mixer is compact and easy to use, but has many advanced features including “D-Pre” high quality mic preamps, a built-in digital effects processor, three-band EQ on all four mono channels, and two “one-knob” compressors.

Matt Livingstone

WORDS BY:Matt Livingstone

Matt Livingstone is the Product Manager for Professional Audio and Music Production at Yamaha Music Australia. With a strong passion for quality sound, he gained valuable experience as a freelance audio engineer across the ditch in his homeland of New Zealand. Matt also owned and operated a live sound production company, where he learned how to avoid feedback and the value of a good roll of gaffer