The input/output section is the basic function of a mixer. This is where the physical connections are made on the unit. For outputs, the minimum a mixer will have is a stereo “main” output, where all the individual channels get mixed to. Some mixers give you alternate “bus” outputs that you can use (more on this later in this chapter). A bus is simply a path that audio can take. In the case of mixers, it's a path inside of the mixer that the audio takes. Better mixers give you individual outputs for each channel, but these mixers tend to be expensive.

There will be one input for every channel that the mixer supports. Other inputs include channel inserts, which are effects that plug into individual channels, and auxiliary inputs, which are effects that can be assigned to any track in the mix. The better the mixer, the more aux effects you get. There is more about aux effects in our discussion on master sections later in this chapter.