Human beings started to make music together long before electronics changed our way of life forever. When multiple musicians send out their sounds as air pressure waves, the air adds all individual sounds to a mix to end up at the listener’s ear, with levels depending on each performer’s distance from the listener.
When groups of performers, or orchestras, are relatively small, they can listen to each other and work out their absolute and relative levels to create the best loudness and mix. When the orchestra reaches a size where performers are far apart, so they cannot clearly hear and see each other anymore, the conductor enters the game. One of the tasks of the conductor, besides controlling the rhythm, is to give the performers dynamic cues regarding the level they need to play at, in order to make the mix as perfect as possible. In a sense, the conductor of an orchestra is the ultimate mixing engineer, controlling the mix with hand and face gestures.
At some point in time electronics started to be used, making it possible to amplify sound so that it could be heard by a larger audience (i.e. public address systems), to transport the sound to another place (e.g. radio broadcast) or to record it for later listening (e.g. tape recording). Each musician’s sound could be converted to an electrical signal, to be processed by electronic ‘analogue’ circuits.
However, to record each individual musician with an individual microphone and then play the sounds back through the same number of loudspeakers to let the air do the mixing would be impractical and very expensive. Instead, engineers decided to use a limited number of loudspeakers for playback. This meant that the air could no longer be used to mix the individual sounds together. An electronic device was required to take over that job: the mixing console.
At first, mixing consoles offered a limited number of input channels and a single output channel to drive a mono loudspeaker system, supporting small group performances. When electronics became more powerful and cost effective, larger mixing consoles emerged. These had more input channels and supported a two-channel ‘stereo’ output, so that the sound engineer - who took over the mixing job from the conductor - could also dynamically decide where the sounds were located across the stage. This was something a conductor could not easily do.
This created a new degree of freedom in music, supporting the rise of many exciting music genres such as pop and rock. In turn, the new music genres boosted the development of additional functions in the mixing console, such as parametric equalisers to allow the mixing engineer to have dynamic control over timbre, effect sends to include electronic effects such as reverberation and delay, monitor sends to provide individual monitor mixes to performers and sub groups to allow more flexible and dynamic two-step mixing. This meant first creating multiple sub mixes, then mixing the sub mixes to a main mix.
To support external audio effects equipment such as graphic equalisers, compressors, limiters and individual channel effects, inputs were fitted with insert connectors. Finally, elaborate cue systems were added to support the mixing engineer in his decision-making.
With audiences growing larger, loudspeaker systems became more elaborate and powerful, often with multiple sub-systems such as subwoofers and delay stacks. To accommodate this, output mix matrix sections were introduced, adding a third mixing stage in the master section, taking its inputs from the sub groups.
Starting in the 1960s, the development of mixing consoles took us to the large scale analogue live and recording mixers in the 1990s, some more than two metres wide, with dozens of input channels and mix buses; channel strips crowded with equaliser, aux, monitor and matrix send knobs; subgroup assign buttons, pan (short for panorama) controls and, of course, ‘long throw’ faders. These flagship consoles used modular channel strip modules, so they could be swapped easily if any of them were broken, and were always accompanied by one or more 19” racks full with external effects and processing equipment.
Approaching the turn of the century, however, the analogue mixing console’s time ran out. Digital mixing consoles and recorders had already started to replace analogue equipment in recording studios and, a little later, the live sound market followed. Live audio would never be the same.