Appendix E Madi Operations; Madi Operations - Sony DMX-R100 Quick Reference

MADI Operations

MADI is an acronym for the Multichannel Audio Digital Interface. It is an audio standard that allows the
simultaneous sample-accurate transmission of up to 56 digital signals (at single-speed sample rates of 44.1 or
48 kHz) over a single coaxial or fiber optic cable. MADI can also operate at double-speed (2 Fs) sample rates of
88.2 or 96 kHz; however, at these rates, the maximum number of simultaneous signals is halved to 28.
The optional DMBK-R109 expansion board adds MADI I/O capability to the DMX-R100. It allows the
console to interface with a wide variety of MADI multitrack recorders, as well as with the optional SIU-100
system interface unit (which provides eight additional expansion card slots — including a remote-controlled
8-channel mic preamp card — thus greatly increasing the total number of physical inputs and outputs available
for routing). The DMBK-R109 expansion board also allows two DMX-R100s to be cascaded together, sharing
many common functions such as bus routings and soloing — even tandem recall of snapshots and titles.
Detailed instructions for accessing MADI functions using the DMBK-R109 expansion board and cascading dual
DMX-R100s are provided in the DMX-R100 Software Version 2.1/2.2 Supplement. Rather than duplicate
these instructions, the purpose of this Appendix is to highlight a number of key and less obvious features.
Interconnections
One DMBK-R109 can reside in a DMX-R100, and it must be installed in card slot 4. The DMBK-R109 card
provides its own dedicated word clock input/output connectors. If you are using the DMX-R100 as master
clock, a separate connection should be made between the DMBK-R109 word clock output and the word clock
input of the MADI device you are using. If the DMX-R100 is being slaved to an external word clock source, a
separate connection should be made between the word clock output of that source and the DMBK-R109 word
clock input.
MADI signal — the audio data itself — can be transmitted and received using either standard 75-ohm coaxial
cable (via BNC connectors) or fiber optic cable. The primary advantage to using fiber optic cable is that it
permits longer cable runs, of up to 300 meters in length (coaxial cable runs should be limited to no more than
50 meters). Both coaxial and fiber optic outputs can be used simultaneously — identical signal will be
transmitted on both — but only one input can be used. A switch on the back of the DMBK-R109 allows you
to select either BNC or OPTICAL connector for the MADI input.
When valid MADI signal is being received and transmitted, status MADI IN and MADI OUT LEDs on the
back of the DMBK-R109 will light steadily. If you see them blinking, the likely cause is that the clock of the
external MADI device is non-synchronous with the DMX-R100. In this condition, audio will be degraded or
not received at all, so check all connnections and settings in the Sync/Time Code window.
If you are using a single DMX-R100, or if you have two DMX-R100s but do not wish to cascade them, be sure
to set the DMBK-R109 Mode Select switch to MADI. For more information on cascading two DMX-R100s,
see page E-5 in this guide.
E-1 E-1

Appendix E MADI Operations