What is MADI?

MADI is the perfect solution for the transmission of multiple audio channels. The technical problems that are found with standard multicore cables are well-known: cable loss, stray pick-up, aging, weight, cumbersome handling, costly etc.

MADI is different using only a thin cable to transmit up to 64 audio channels and over a distance of up to 2000 meters!

Optical Fibre Cables

Multimode/Singlemode – Optical fibre cables for RME MADI systems
All RME MADI products provide optical I/O for the use with “multimode fibres”. “Singlemode” is available on request for all units and allows an operation within existing singlemode networks, without additional expensive converters.

Why glass fibre optics?
There is a constant growing demand for huge data transmissions which means that traditional twisted-pair copper cables will in the future not meet the requirements of ethernet networks and with Gigabit or 10 Gigabit, traditional cables will of course reach their physical limits. Only optical glass fibres will meet future transmission demands.

 

Basics
Multimode optical fibres (MADI standard) consists of a core, a cladding and a primary coating. The light-transmitting cable core is made of fibres of glass, and carries the actual signal. The coating totally reflects the light and thus conducts it within the core. The coating is a protective layer against mechanical damage and is usually between 150 and 500 µm in thickness. Between the cladding and the coating, there is a fine layer of lacquer (2 to 5 µm) to keep out moisture. The coating is usually made of soft plastic, but special versions with extremely stable coatings are also available. And now, optical cables can be manufactured cheaper than copper based cables.

A singlemode fibre is a glass fibre with reduced diameter.

Technologies (example: multimode fibre)

• Diameter core: 50 µm or 62.5 µm
• Diameter wrap glass: 125 µm
• Outside diameter: 4 – 9 mm
• Label: 50/125 (orange) or 62.5/125 (blue)
• Transmission format: Multimode
• Max. transmission width: 2000m

 

Optical fibres have become a new standard. Many manufacturers offer cables and connectors, and even complete road-ready systems with cable drums, with up to 2000m in total length. Please ask your RME dealer for the supporting product line of cables from Alva Cableware (RME approved digital audio cables).

 

Connectors
Like most other MADI devices, the RME MADI products use the common SC-Plug (IEC 874-19) for optical connection. The SC connector is compact and ensures a reproducible and constant connection quality. The SC duplex version combines two fibres. An automatic interlock prevents accidental interruption of the connection. The fibre type, explicitly required for optical MADI connections, must be a 50/125 µm or 62.5/125 µm multi-mode fibre (MM fibre).

Advantages of Optical Fibre compared to Copper Cable

• Insensitive to electromagnetic disturbance
• Optical cables can be run parallel to power cables etc.
• No crosstalk, hum or potential differences
• No influence on audio quality also in long distance applications
• Considerably lighter in weight

Optical fibres have become a new standard. Many manufacturers offer cables and connectors, and even complete road-ready systems with cable drums, with up to 2000m in total length. Please ask your RME dealer for the supporting product line of cables from Alva Cableware (RME approved digital audio cables).

 

MADI Multinorm

RME supports the following MADI formats/modes:

Type	Channels	Resolution	Sample frequency	Frame Rate Word Clock	Hints
Standard 1	56	24	48	48	with ±12.5% Varispeed
Standard 2	64	24	48	48	without Varispeed
Double Wire 96/48k Mode	32	24	96	48	with sample frequency doubled the channel data will be split on two channels – ADAT > S/MUX – Tascam > Dual Line
Quad Wire 192/48k Modus	16	24	192	48	with sample frequency quadrupled the channel data will be split on four channels – ADAT > S/MUX4
96k Frame	32	24	96	96	alternate transmission mode with Double Speed