Multiplex

In music creation and technology this term applies to sending two or more signals over one channel or wire. To do this a device most commonly known as a multiplexer takes multiple individual signals and encodes them in such a way that they can be transmitted as a single more complex signal. At the receiving end there is generally some type of demultiplexer that decodes the information. This is a very simplified and generalized explanation, but contains the gist of the concept. A few types of multiplexing are: FDM – Frequency Division Multiplexing, where each signal is assigned a different “carrier” frequency; TDM – Time Division Multiplexing, where each signal is assigned a fixed time slot in a fixed rotation; STDM – Statistical Time Division Multiplexing, where time slots are assigned to signals dynamically to make better use of bandwidth; WDM – Wavelength Division Multiplexing, where each signal is assigned a particular wavelength (this is frequently used in fiber optic transmissions). Multiplexing is becoming more frequently used in musical equipment all the time (even though in many instances it is not apparent to the user) and is a key to making the Internet or any computer network operate.