MADI stands for Multichannel Audio Digital Interface, or AES10 is an Audio Engineering Society (AES) standard electronic communications protocol that defines the data format and electrical characteristics of an interface that carries multiple channels of digital audio on a single coaxial or fiber cable. The MADI standard includes a bit-level description and has features in common with the two-channel format of AES3. It supports serial digital transmission over coaxial cable or fibre-optic lines of 28, 56, or 64 channels; and sampling rates of up to 96 kHz with resolution of up to 24 bits per channel. Like AES3 or ADAT it is a Uni-directional interface (one sender and one receiver).
Sampling frequency
32 kHz to 48 kHz ± 12.5%, 56 channels
32 kHz to 48 kHz nominal, 64 channels
64 kHz to 96 kHz ± 12.5%, 28 channels

MADI is being used: as a multi-Channel link between mixing consoles, DAWs or multi-track recorders or other digital outboard gear, as a transmission format in large scale digital audio routing systems, to transmit digitized microphone and line signals from a stage box to a theater or studio mixing console. With MADI products you can combine different audio standards such as AES/EBU, ADAT and TDIF into one MADI audio system. Any MADI installation will remain an open system, easily expandable to any size on demand, using devices or products from many major pro audio manufacturers.
A flexible analog multi-channel connection includes different components:
Multicore cable - circuit connectors - breakout box - stagebox - signal splitter.

WORD CLOCK: The precise and accurate timing of digital audio samples is critical to the correct operation of interconnected digital audio equipment. The 'metronome' that governs sample timing is called the Word Clock. However, word clock does more than merely beat time; it also identifies the start and end of each digital word or sample, and which samples belong to the left or right channels.
Digital interfaces such as MADI, AES-EBU and S/PDIF embody clock signals within the data stream, but it is often necessary to convey 
a discrete word clock between equipment as a square wave signal running at the sampling rate. Dedicated word clock inputs and outputs on digital equipment generally use BNC connectors.