Input Devices

For our purposes, the term "input device" refers to anything that can provide an audio signal for the system to process.  Common input devices include microphones, instrument pickups, computer or synthesizer outputs, and effect processors.

Output Devices

The term “output device” in this guide refers to the end-of-the-line, where the audio signal reaches its final point in the system.  In a live-sound setting, this may be a speaker, an in-ear-monitor system, or a recording device.

Processors

For this guide, a processor is any device that intentionally transforms the quality or content of the audio signal.  Equalizers allow you to adjust the emphasis of certain frequencies in the signal. Dynamic processors automatically adjust levels based on certain conditions. Effect processors encompass a wide variety of sonic possibilities.

Mixers

In most systems, the mixer is where the bulk of the work happens.  In its simplest form (i.e. a mixer without any processors), the mixer adjusts the levels of one or more inputs to control its proportion to one or more outputs.  Most mixers also include equalizers, which are discussed in the Processors section.  In a mixer with dedicated channel strips, the signal path for a channel will typically move from the top of the channel strip to the bottom.

Amplifiers

Amplifiers receive a relatively weak audio signal, apply power to multiply/boost the strength of a signal, and send the stronger signal to the final device - usually a speaker.  Power Amplifiers are discussed in the output devices section; pre-amplifiers are discussed in the mixer section.