Difference between revisions of "Mixing Boards/Consoles"

Revision as of 14:06, 11 March 2015

Mixing boards or mixing consoles (also called mixing desks, soundboards, or just mixers) allow you to adjust, mix, and route audio streams. They can be analog or digital, and can be physical or virtual (software).

Channels

Each input and its associated controls are referred to as a channel or channel strip. The term also sometimes covers outputs when they have a similar appearance. The channels are typically arranged in single row, with the inputs on the left and outputs on the right, although larger mixers may place the outputs in the middle. This is why they are called channel strips - each channel looks like a vertical strip of tape.

Channels often feature numerous controls that affect only that channel. They may have different types of input jacks depending on what instruments or gear are designed to input into that channel, and may accept mono or stereo input. They may contain mic pre-amps and phantom power.

Buses

Some channels are called buses, which is a very generic term but generally refers to channels that are handling groups of inputs...or other buses. For example, the master output channel is often called the master bus, as all the other channels are routed through it before being sent out of the mixer. There may also be an auxiliary (or "aux") bus for an alternative mix. Then there may be buses for certain instruments that require multiple input channels. For instance, drums typically require numerous microphones to capture the entire kit's sound - all those mics are fed into separate input channels which are all routed to a drum bus, where they can be processed together before being output to the master bus. This makes it much simpler and quicker to adjust the volume of the drum kit as a whole, for example.

Volume Faders

The most obvious and common element of each channel and bus is a volume fader. This is the thing you slide up and down, consuming most of the space for the strip, and it adjusts the volume of the channel. The reason such large space is devoted to the volume faders is because the most instrumental part of the mixing board is to ensure all the instruments are mixed at the correct relative volumes. Sliding faders give the user instant visual feedback on the mixer's volume setting for each channel and allow fine adjustments. That said, some mixers are designed to be smaller and may forego faders in place of simple knobs.

Trim

Since mixing boards are typically working with microphones and a wide range of instruments, incoming volumes can be radically different from channel to channel. A trim pot/control is used to attenuate the inbound signal before it hits the fader or is sent to other gear. This helps avoid clipping as well as maintaining good gain staging. It can be used to roughly level or normalize all the channels, while the faders are used to make some instruments more prominent or otherwise create a pleasing mix.

It may seem a bit counterintuitive to have two ways to control volume, but remember that certain processing occurs before the signal is affected by the fader, such as sends to external gear, amplification by a microphone pre-amp, and adjustments on the channel strip itself. Too hot of a signal can result in unwanted distortion. Furthermore, an extremely hot signal would require sliding the volume fader very low to normalize the instrument with others. This greatly reduces the volume fader's adjustment range, making it more difficult to fine-tune that channel's volume.

Solo

A solo (or cue) button on the channel mutes all other channels, unless they also have their solo button pushed. This allows you to quickly monitor a particular channel (or several) apart from the full mix. It saves you the trouble of having to push the mute button on every other channel.

Mute

Most channels feature a mute button that does exactly that - it mutes the channel, preventing it from being output to any buses. In other words, you will no longer hear it in the mix. This can be useful if an instrument starts feeding back, or a guitar amp malfunctions, or something similarly-awful happens that starts causing the channel to fill the mix with unwanted noise. It can also be used to compare a mix with and without a certain instrument to determine if the instrument is helping or hurting the mix.

Balance/Pan

Mono channels typically have pan controls, while stereo have balance controls.

Send/Receive