Mixing Console
From WikiRecording
A Mixing Console (or simply Mixer) is a device used for routing, altering, and summing audio signals.
Contents |
Input/Outputs
The inputs and outputs provide the means to get audio in and out of the mixer.
Channel Inputs
Typically 1/4" TRS and/or XLR inputs. Many mixers include phantom power on some or all of their XLR inputs.
Some mixers may also include insert points for inserting effects to individual channels, or direct outs for directly routing channels to digital recorders, tape decks, or other recording devices.
Aux Sends and Returns
Aux sends and returns allow you to route the signal from (and back to) the mixer. This is typically used for blending effects, or for live monitor sends.
Main Outs
The sum of all the audio passing through the mixer is available from the main outs.
Other I/O
If available, submix busses will have their own dedicated outputs. Other common I/O includes tape in/out, headphone out, and talkback microphone input.
Channels
A mixer channel is an individual signal path for getting audio into the mixer, and processing that signal. In order to qualify as a mixer, there need to be at least two channels.
Channel Layout
Mixer channel features and appearance vary widely, but typically have at least the following parts.
Input Controls
The input section typically includes a gain (or trim) control to adjust the amount of signal coming in to the channel, and a phase switch. A low-cut switch is another common option. If the mixer provides individual phantom power (as opposed to a global switch), it will usually be in the input section as well.
Equalization Controls
Almost all mixer channel strips include some sort of EQ on each channel. More expensive mixers will offer more flexible EQ sections. The minimum is typically high, mid, and low EQ with fixed frequency and Q points. More detailed EQ sections offer more control over the frequency bands.
Auxiliary Sends
The Aux Send controls allow you to send the channel's signal to the aux busses. This can be useful for adding effects to a signal, or simply routing the signal to another output bus for another purpose, such as stage monitoring. Many mixers have multiple aux busses, and each channel will have a rotary control for determining how much of that channel's signal is routed to each aux bus.
Level/Pan and Routing Controls
The channel level control (typically a fader) determines how much of the overall signal is routed to the output busses selected for the channel.
The Pan control allows you to fix the location of the channel's signal in the stereo field.
On mixers with multiple output busses, there will be switches for choosing which busses the channel's signal will be routed to.
A channel strip typically also provides a mute button to silence the channel, and a solo button to mute all other channels and play only that channel.
Master Section
The master section of a mixer provides control of the levels of the individual busses, including the master stereo bus. It will also provide send and return level controls for the aux busses.
High-end mixers can have very complex master sections with many more features not covered here, including talkback and monitor selection.
Metering
To monitor signal level, a mixer will usually provide some kind of metering, typically in the form of stepped LED's that are in the form of a PPM Meter or VU meter. PPM stands for Peak Program Meter and is more common in modern consumer audio equipment, VU stands for Volume Unit, and measures the average volume level of an audio signal.
Channel Meters
Many inexpensive mixers don't provide channel level meters, but will at least provide a clip indicator to show when a channel is overloaded.
Master Bus
Most mixers, even inexpensive ones, will include some metering for the master bus.
