Most mid to high-end mixers draw from very similar feature sets, and tend to vary only in quality and channel and/or feature quantity. Well now take a closer look at some of these basic features, as their explanation should provide a better understanding of the fundamentals of mixing, and will be useful in a broad variety of situations.
The large majority of a mixers surface is usually made up of channel strips - these are normally identical vertical strips running across the mixer which allow individual processing and control of each input signal. Most channels are usually mono, and these are generally used for microphones and sometimes instruments such as guitars. Mixers will often also incorporate a handful of stereo channels which allow for the connection of stereo keyboards, playback devices and submixers, and tend to offer fewer features than found on typical mono channels. Each channel strip is made up of multiple signal processing controls which we will look at in more detail later in this section.
As mentioned previously, subgroups allow the grouping of individual channels before their signal is sent to the master section. A fader (or two) allows the user global control over a groups level, particularly useful for backing vocals and drum kits for instance. They may have their own outputs for multi-track recording, as well as insert points and/or aux sends to simplify effects and signal processing. Mixers with subgroups will have a selection of push buttons next to the channel faders to determine which group(s) the signal is routed to. Groups are generally stereo, in which case panning information from the channel is also transmitted to the group.
This is where all the signals are brought together, ready for any final processing before being distributed to the outputs, which can range from a single stereo out, to multiple outs including sends for tape machines, speakers, headphones and more. Insert points may also be found here, along with the master fader(s), some form of metering, and possibly further EQ and built-in effects processing, particularly on mixers aimed specifically at live use.