Digitising your studio to transmission chain: Aaron Alphonso’s technical advice

“Soundcards are so very 2005.”

Macquarie Media’s Chief Technology Officer Aaron Alphonso, this week delivered a wide ranging technology presentation in Malaysia at the annual Digital Broadcasting Symposium.

He discussed the most important technological considerations when digitising your studio to transmitter chain. Three key areas to consider are:

  • Audio Mixing, Routing and Delegation
  • Playout Systems
  • Systems Integration


Audio Mixing, Routing and Delegation

This is the system that mixes the various audio sources in our studios and ensures that it sent to the right transmitter for the right service.

These are often complex systems with many components. They generate a lot of control data, as well as being remotely controllable.

There are three main considerations when looking at existing systems or integrating new systems: Monitoring and Control APIs, Audio over IP usage, and Automation

Monitoring and Control APIs

Most modern routing and control systems will have some way of interacting programatically via a remote control protocol or an API (Application Programming Interface). 

These used to be highly proprietary protocols that required specialist information to do anything useful with, and as such it was difficult to use these without substantial effort and development cost. If you are considering a routing system, select one that relies on, or at least has support for, open and simple protocols, even web standards

Audio over IP

Aaron recommends the adoption of a full Audio over IP based system for your audio routing needs. The primary reason for this is ease of scalability and speed of implementing new features.

With analogue or more traditional digital setups, stations are often limited by the number of outputs and inputs. If we needed to add new features or functionality traditional setups are quite limiting.

“An example is one of our stations in Perth. It is 100% Audio over IP based. We had to install a bunch of apps to ingest audio for a podcasting platform. Instead of messing around with wiring new audio, installing new cards,  purchasing expensive broadcast hardware, all we had to do was install the software on an adequately spec’d machine. 

“Once we installed the Audio over IP “virtual sound card” drivers, we had the ability to route every single point of audio in the station to that computer  and subsequently to the software we needed.”

The flexibility and scalability benefits that Audio over IP provides in a radio studio environment cannot be overstated, and will result in speedier deployments of new digital audio features such as podcast recordings and smart speaker integration.  


The ability to automate audio mixing and routing systems allows ease of scheduling workflows such as background recordings, routing of audio to sub channels, content marking and tagging.

With good integration the playout system can be used to automate functionality within the routing system to do things such as automating clean feeds of news:

  • routing just the news audio fader to a software recorder 
  • starting that recording, then ending it
  • which could then trigger a series of transactions to feed a website output or publish to a smart speaker provider
  • providing scheduled audio feeds to various digital radio channels that may not have their own dedicated news feeds

It is important that the routing system can be controlled so that it can extend its value in the broadcast chain.




Playout Systems

These are the studio computers that play music programming and commercial content. They should be “the natural home for where all extended services for Digital Radio elements live, or at least the point where these elements are triggered,” says Aaron. These include graphics and visuals, hyperlinks,  billboard information and other elements.

Billboard/Now Playing Info

There are many aspects to consider in picking a system. The first is the ability to dynamically export “Billboard or Now Playing”  information.  It should be a minimum requirement for a station’s digital assets, whether it be Digital Radio, website information, streaming audio or other outputs.

At the very minimum for music stations, the ability to display artist and track information should be implemented to take advantage of the added textual data display capabilities of digital receivers.

Tagging of Content Types

The ability to tag content types is critical in a playout system. It is important that this is done from the start during the ingest process to ensure good functionality for web and hybrid radio systems. A lot of additional revenue can be gained from programmatic advertising on web streams but this requires solid triggering of commercial breaks either through tagging or through some other form of signaling. This signals the streaming servers to replace the ads you would hear on the radio with dynamically served ones that may be more suited to your listeners’ location, interests or preferences – these are generally more valuable to the advertiser.

With poor content tagging and signalling stations may not be able to take advantage of such features, or the listener experience may be a poor if there are issues with timing that may cause dynamically served audio to overlap or crash into normal programming.

Extended Library Management Capabilities

Pick a system that has a high level of customisation capability within its library or asset management features. This means the ability to store a lot of extended data alongside a traditional audio asset, as well as to define and customise the types of data to be stored  This will protect against rapid obsolescence and allow for new and upcoming features that may require some form of linking to an asset.

Examples of the type of data to consider include album art, related images,  hyperlinks, extended text information and information about related audio.

It is a good idea to mandate the inclusion of visual information such as album covers, automatically generated weather slides, branding images, presenter photographs to every audio asset. For example, when an announcer is talking there should something relevant on the screen, or if an ad is playing there should be an associated graphic, not just the album art from the previous song that played.

This guarantees a consistently rich experience on devices that support visual information such as Digital Radio, Hybrid Radio and streaming radio receivers.  The inclusion of hyperlinks could be very useful for Hybrid Radio purposes where there is the ability to interact through a data connection. Hyperlinks may contain direct links to show pages, further reading, advertiser information or links to related podcast pages.

It would be best practice to ensure that file sharing and hosting configurations allow audio and related assets to be accessed by all elements of a system. Of course it is important to maintain some degree of separation from normal user interaction, but this is easily done by credentials and segregated VLAN access. Also remember to have regular backups so the effort put into rich assets is not lost.


Systems Integration

Things to look out for when connecting these systems together that will allow automated and meaningful generation of data for digital platforms.

Routing and layout systems will not work usefully unless they are held together by tight and meaningful systems integration.

DIY Considerations

If a station intends to use its own internal resources to develop tools, then the adoption of open standards and web protocols is very beneficial, because development talent who can understand web technologies are readily available.

Open and mature web based standards and protocols will allow for a wide pool of talent to develop solutions using systems they know well.Preference should be given to systems that support open and commonly used web standards.

When developing integrated systems in-house, focus on automation. Aim to take away as much additional work from production staff as possible and set up systems to automatically generate content for digital platforms based on data and information already pre-associated with your audio assets.

Premium managed services

There are off-the-shelf solutions that have been written to plug into many systems from major providers that have all this digital content authoring functionality built in.

When contemplating an off the shelf system, ensure that the provider has the capability to talk to all your systems: routing, playout, multiplexer systems, website CMS, streaming servers, etc, or at least is willing to add plugins for it. Of course these things come at a cost.

Some high end playout and media asset management systems already have this functionality built in.


He concluded saying, “soundcards are so very 2005.”


Several other good tips came up in other technical presentations at the digital broadcasting summit.

Security of your data, your playout systems and your hardware is important. Change the default passwords!

If you are buying equipment from multiple suppliers make sure it is compatible. A digital desk sends lots of pulses per minute so a router designed for an office system that does not require fast networking will be too slow or will crash if used with an IP driven digital mixing desk.

When there is a problem it is easy to route around it, but you need engineers who can then trace the fault to its source and fix the original problem, otherwise it will keep recurring.

Peter Bruce from the IABM (pictured) reminded delegates that IP is coming to replace all those cables currently in your system with ‘one cable to rule them all.’


For more reports from the 2019 Digital Broadcasting Symposium in Malaysia, see our other publication, AsiaRadioToday.

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