What is MADI? A guide to the audio format

If you work with broadcast audio and frequently face the problem of how to move a lot of channels of audio over a long distance, such as outside broadcast or around a large production environment, then you're probably already familiar with the MADI protocol. If not, then it could be time to embrace the technology and take a break from hugely heavy multicores, complex switching systems and limiting audio-over-Ethernet solutions.

What is MADI?

Put simply, MADI (Multi-channel Audio Digital Interface) allows you to send up to 64 discrete channels of audio via a single fibre optic cable or coaxial cable and over distances of up to 2km. It supports audio formats up to 24-bit/192kHz and doesn't use lossy compression. For this reason MADI has become an obvious choice for many of the largest outside broadcast operations, and for creating an audio network around a building where bulky multicores would be undesirable and prohibitively expensive.

The MADI format has been adopted my most of the leading pro audio manufacturers, including AVID, RME, Euphonix, SADiE, SSL, Yamaha and Soundcraft, and products that use the technology range from I/O formats on consoles, audio capture cards for computers and remotely controllable mic preamps (the MADI protocol also supports control data).

Flexibility

In addition to a huge channel count and range, the other key advantage of MADI is flexibility. The individual audio channels within a MADI stream can be routed, split and recombined independently, enabling a source to be sent to multiple destinations or a single recorder to capture from multiple sources. RME, for example, manufacture an 8x8 MADI router capable of accepting up to 512 channels of audio and routing any of them to any combination the 512 available outputs.

Remotely controllable and taking up just 1U of rack space, that's some serious flexibility! In fact, even RME's MADI PCIe capture cards offer this sort of flexibility, as the onboard TotalMix allows for flexible routing of all input and output streams independently of recording.

Capabilities

A single MADI stream will give you:

• 64 channels of input + 64 channels of output at 24-bit 48kHz
• 32 channels of input + 32 channels of output at 24-bit 96kHz
• 16 channels of input + 16 channels of output at 24-bit 192kHz
• Range: 2000m over fibre (SFP) or 100m over coaxial copper (75Ω, bnc)

The opportunities of MADI for broadcasters are huge. It offers a level of flexibility that is almost impossible to achieve with standard analogue cabling. With fibre cable costs (and weight) being a fraction of that of copper multicore, it offers a lighter, cheaper, more flexible, more robust and faster deployment solution for creating a fixed or portable audio network than any other system currently available.

If you want to know more about audio formats and systems, give us a call on 03332 409 306, email audio@Jigsaw24.com or leave us a comment below. You can also keep up with more news, reviews and offers by following us on Twitter (@Jigsaw24Audio).