UNDERSTANDING M-MADI
ALLEN & HEATH M-MADI is one of a range of option cards which can be fitted to an iLive to enable integration with other systems. Multi-channel Digital Audio Interface (MADI) is an industry standard protocol for digital audio supported by many manufacturers.
- Typically MADI is used for multi-channel recording and playback. Long coaxial cable runs are possible depending on the driver capability of the hardware, making it a frequent choice of equipment interconnection in gigs, studios, and broadcast applications. E.g. a 150m (490’) cable-run is reliable M-MADI to M-MADI using 75ohm Belden 1505A cable. MADI cables are directional, so there is one connector for MADI-out, and one for MADI-in.
- It is a point-to point interface between a source and a destination.
M-MADI gives access to 64 input and 64 output channels and can be fitted to:
- Port B expansion slot in iLive fixed format MixRacks (iDR-16, iDR-32, iDR-48 & iDR-64) or expander (xDR-16)
- Port B and/or Port A of iLive modular MixRacks (iDR0, iDR10) if fitted with the RAB-2 standard.
- Port A of iLive modular Surfaces 80/112/144/176 if they are fitted with the new RAB-2 standard.
- I/O Module slot in GLD-80.
The Allen & Heath M-MADI-A 64-Channel MADI Card is for the iLive console and is used for bi-directional transmission of digital audio and word clock signal over 75 ohm coaxial cables. The M-MADI card will also support word clock for accurate digital sync.
FEATURES at a glance
Dual link mode: connect and stream with two separate devices. Inputs to the system can be patched from the two MADI streams in blocks of 8, while the same outputs are broadcast on both links.
Redundant mode: Link 1 and Link 2 can be used as a redundant pair. Audio and clock will continue if one of the cables fails.
Aux BNC:
• Out 1 mirror: This mode duplicates the MADI stream ‘Out 1’, useful for splitting signals to multiple devices.
• In 1 Thru: The MADI stream ‘In 1’ is passed ‘thru’, allowing daisy chaining of signals to an unlimited number of devices. The signal is fully reclocked and buffered for optimal reliability, and the signal will automatically switch to ‘In 2’ if ‘In 1’ fails in redundant mode.
• WordClock IN: Provides a word clock input to sync the system from an external (48 KHz) source, for example a distributed word clock.
This is a high-sensitivity input, locking to a word clock signal as low as 200 mV p-p.
• WordClock OUT: A standard word clock output to allow other systems to sync from the iLive system, useful when connecting to 3rd party MADI devices which may not be able to sync from the MADI stream.
M-MADI SPECIFICATIONS
- Ultra high-sensitivity inputs: An equalizing receiver circuit, originally designed for HD video, allows error-free reception of signals where a normal receiver would not even detect that a signal is present. As a consequence, connecting two A&H MADI cards together allows cable runs in excess of 150m (triple the standard!), and electrical noise immunity is increased all round. All inputs, including the word clock input, are also AC-coupled, to avoid potential ground loop problems.
- Flexible Syncing: Users may select either of the input MADI streams (Link 1 or Link 2), or the ‘Aux’ BNC word clock input, when selected, as the system clock source. Note that iLive is a 48 KHz system, and any selected clock sources must be 48 KHz