Can 48 channels be controlled from the CDC four:m and CDC four?

When the stagebox is connected to the CDC four:m or a CDC four, two extra “layer” buttons are enabled allowing access to the extra channels.

Can 48 channels be controlled from the CDC four:m and CDC four?

To connect a CDC four:m / four to an iPad you will need TabMix installed on the iPad, which can be downloaded from the Apple App Store, a wireless router and an Ethernet cable.

  • To connect to an iPad you will need to first plug in a wireless router into the CDC four:m / four via the Ethernet port on the back of the console with the Ethernet cable.
  • Power up the wireless router
  • Power up the CDC four:m/ four
  • Once the console is booted up press the SYSTEM button to the left of the screen on the CDC four:m / four
  • Then press the SYSTEM function button below the screen on the right hand side
  • This will then you give an IP address of the CDC four:m / four. It should be something like “192.126.***”
  • Open up TabMix on the iPad
  • When prompted for an IP address for the console type in the IP address from the CDC four:m / four.

You should now have the console connected to the iPad.

How do I connect my CDC four:m / four to an iPad running TabMix?

The CDC four and CDC four:m can have an additional 32 mic / line analogue inputs with the addition of a CDC I/O 3216 stagebox. The stagebox also allows the 16 line outputs to be on stage. To connect the stagebox to the CDC four or CDC four:m it must have a MegaCOMMS card fitted.

How do I expand the channel count on my CDC four:m or CDC four?

CDC fourm Battery Replacement

The linked document provides Instructions on (a CDC four has a different procedure).

Click to open: Cadac-CDC four-m Battery Replacement-DOC2-June 2016

How do I replace the back-up battery in a CDC four:m?

Below are the instructions on how to update the firmware on the CDC four:m:

1. First, make sure any scene memories are saved to a USB memory stick before updating the console.

2. Connect the CDC four:m to the internet via an RJ45 cable inserted into the Ethernet socket on the rear panel of the console.

3. Boot the CDC four:m into Maintenance Mode either by:

a.  Switching on the console while pushing in the recessed switch labelled RESET on the back panel. Release the switch only when the Cadac logo is on the screen.

b.  Or select SYSTEM / SYS SETTINGS / MAINTENANCE, enter the pin number “1969” using the ADJUST encoder and arrow buttons. Press ENTER to select OK. Press ENTER again.

4. When the CDC four:m is in Maintenance Mode, select NET UPDATE (press F5) and wait for message to report the update is complete.
5. Disconnect the RJ45 from the console.
6. Power cycle the unit twice to initialise the new firmware.

After this you should have the latest version of firmware on your console.

How do I upgrade the firmware on a CDC four:m?

If you are finding that your CDC four or CDC four:m is recalling odd audio parameters when you are booting the console up, it maybe a sign of the internal backup battery failing.

The audio parameters of the CDC four and CDC four:m are stored in RAM memory, which is powered by a 3V lithium battery when the mains power is switched off. After a couple of years the battery will be below its optimum charge and this may result in unexpected audio parameters being recalled by the console when powered up.

We would therefore recommend that you change this battery for a new one every 12 months.

Below are links to specific instructions for replacing the internal on both the CDC four and CDC four:m:

Please note these instructions are model specific!

I am experiencing odd audio parameters being recalled by my CDC four / CDC four:m. What’s happening?

The login details for the customer repository are:
Login: customer
Password: cadac1968

What are the login details for the Cadac customer repository?

The CDC four:m uses two character “mnemonics” for the inputs and outputs that may be assigned to sockets on I/O stageracks. These can be seen in the Socket Assign page by pressing Function Button 3 labelled Assign Socket.

Cadac CDC four-m socket assign

The mnemonics are:


C17 to C48  Channels 17 to 48



MR, ML, MM Master output right, left and mono
G1 to G4 Group output 1 to 4
A1 to A8 Aux send output 1 to 8
mL, mR, mM Monitor Left, Right and Mono
TL, TR Tape output, Left and Right
PL, PR Phones output, Left and Right
M1 to M4 Matrix output 1 to 4


Please Note: The local sockets on the rear panel of the CDC four:m are hard-wired and cannot be re-assigned.

What do the letters mean on CDC four:m Socket Assign screen?

MegaCOMMS is Cadac’s proprietary digital audio protocol.

MegaCOMMS is a robust, TDM (time division multiplex) system. Control data is embedded within the data stream, so that no audio channels have to be sacrificed for this purpose. The high bandwidth available means that the current implementation of MegaCOMMS can carry 128 channels of 24-bit, 96 kHz audio, plus control data, plus clock, bi-directionally, up to 150 metres via a pair of RG6 coaxial cables.

What is MegaCOMMS?

Cadac specify RG6 3G 75 Ohm 18 AWG solid bare copper, super high-resolution coaxial to ensure that the cable is capable of handling over 4 times the data required for MADI.

What spec of coaxial cable should I use for MegaCOMMS?

The CDC four:m has the addition of a 6 x 4 matrix, combining the 4 group outputs and the LR master into a further four outputs.

These outputs are part of the extended outputs from the CDC four:m which are only available if you use an I/O stagebox with more than 16 outputs (CDC I/O 6448, CDC MC MADI, CDC MC Dante etc.).

Select the CDC four:m output layer and press Function Button 3, labelled Assign socket. The Matrix outputs, M1 to M4, are assigned to sockets 25 to 28.

Cadac CDC four-m socket assign

If you are using the CDC four:m with a CDC I/O 3216 stagebox these outputs may be reassigned to one of the 16 sockets available but this will entail giving up the outputs that are currently using them.

Where are the Matrix outputs on a CDC four:m?

The glowing connectors on the rear of the console and on the rack mount units are MegaCOMMS ports.

The red – Rx – connectors are the receive or “in” ports and the blue – Tx – connectors are the transmit or “out” ports.

Why are there red and blue glowing coaxial connectors on the consoles and rack units?

RG6 is a very robust cable and the BNC connectors used are professional grade connectors and we are not limited to 100m runs of Ethernet technology – MegaCOMMS will easily run up to 150m on coaxial.

Why does Cadac use RG6 coaxial cables rather than Ethernet?

No – unless the cables you are using are RG6 3G 75 Ohm 18 AWG solid bare copper, super high-resolution coaxial.

MegaCOMMS requires a cable that is capable of handling over 4 times the data needed for MADI.