Digital radio: All you need to know

1. What is digital radio? Why is it better than AM/FM?
Digital radio is to normal radio what digital television is to your standard analog TV. It's the most significant upgrade to happen since the introduction of FM in Australia in the 1970s, and promises just as much of a leap in quality as FM is over AM. Digital radio works by turning both sound and data into digital signals at transmission, and then decoding them at the other end using digital radio receivers. The result is close-to-CD-quality sound output.

While AM/FM radio quality can suffer from interference caused by signals bouncing off walls, buildings, hills and other structures, digital radio receivers have built-in technology that cleans and filters transmissions, making interference practically non-existent. What's more, with data now able to be sent as part of the signal, digital radio receivers with LCD screens can also give listeners information such as song names, cover art, news, weather and more. In fact, the new DAB+ standard gives you the ability to rewind broadcasts by up to 15 minutes.

The Pure Evoke Flow, a DAB+ radio with OLED screen (Credit: Pure)

2. What can digital radio do?
First and foremost, digital radio gives you better sound quality that's better than FM, and it is interference free. Digital radios are also easier to tune — instead of fiddling with a dial to find the strongest frequency for a station, listeners will be able to choose a station by name from a menu, with the digital radio automatically locking on to that signal at a push of a button.

Perhaps digital radio's most groundbreaking features lie with its data capabilities. With information able to be sent along with sound on a digital radio transmission, listeners that have digital radios with LCD screens can receive information such as what song's currently playing, what station they're on, simultaneous news feeds, phone numbers that correspond to the ads they're currently listening to, album art and much more. Digital radios with onboard storage allow you to pause live radio or rewind, just like a digital set top box works for digital television.

Austereo stations 2DayFM and Triple M have announced their support for the extended features of DAB+, and are beginning to transmit cover art over the air for the next generation of compatible radio receivers.

3. Do I need a new radio to listen to digital?
Unlike digital television, which can be seen on your existing TV with the addition of a set top box, you'll need a brand new radio to be able to listen to digital transmissions. A digital radio differs from a normal FM or AM one because it has a chip inside that allows it to tune into the new DAB+ standard.

N.B. Unlike digital TV, the analog signal will remain, and you won't have to upgrade to digital unless you want to.

4. Where can I listen to digital radio?
Before you rush out to buy a digital radio, be aware that the coverage areas for digital radio are still quite limited. While most state capitals are online, many regional areas will be missing out. At present, digital radio covers 62 percent of the population. Commercial Radio Australia has a website devoted to digital radio, and you can check if your area has coverage and what stations are available here. Transmissions of DAB+ officially begun in May 2009, with Perth coming online first followed by Melbourne, Adelaide and Brisbane. While broadcasts are now active in Sydney the official launch date is 4 June 2009.

Trials for digital radio started in December of 2003, and since then the standard has changed from the original DAB to the newer DAB+. DAB+ is a more efficient method of broadcasting music, and is based on AAC, a codec also used on iPods. It's more efficient than the old standard and means a higher quality signal is possible than before. As a result, if you bought a digital radio before last year you may find that it no longer works. But, check with the manufacturer if this is the case as an update may be available for your device

In Sydney, some of the stations are already making use of digital radio's advanced data capabilities. 2GB, for example, has an NRL Score service for rugby league. Listeners to the station with a digital radio (with an LCD screen) will see up to the minute scores during the game and get details on try-scorers, stats and players. Another example is 2CH, which has been broadcasting track listings, news and headlines with their digital transmissions. Music station Nova broadcasts song names and artists.

5. What about the rest of Australia? When will digital radio be available everywhere else?
The Federal Government has not mandated any digital radio requirement for regional areas, instead opting to allow radio broadcasters to move at their own pace. The Government, however, has indicated previously it is willing to subsidise any bush rollout, and has urged broadcasters to "commence trials of digital radio in regional areas so technical and other issues can be resolved". The bottom line for regional listeners is a much longer wait than their city cousins for digital radio. Don't hold your breath if you're outside of the five capitals above — it could be years at least before digital radio is widespread throughout Australia.

Some DAB+ radios, such as this Yamaha TSX-120 also include iPod docks (Credit: Yamaha)

According to guidelines set down in 2005, broadcasters now have six years from the commencement of digital broadcasts in an area to make sure the coverage of digital is as widespread as current analog transmissions.

As we said before, the Federal Government has not set any switch-off date for analog radio signals, seeing digital radio as a supplement rather than a replacement. What that means is analog radios aren't about to become useless any time soon. Also unlike TV, there is no requirement for broadcasters to simulcast their programming in both analog and digital. This frees up radio stations to broadcast some content exclusively on digital, such as the three-month "Pink Radio" channel running to coincide with Pink's Australian tour.

6. Where can I buy a digital radio?
There are quite a number of digital radios available, and range from portables, hi-fis, in-cars to PC card receivers. Look out for our digital radio roundup. For a full list of retailers, visit Digital Radio Plus site. Digital radios can be purchased through retailer Len Wallis Audio; Pure receivers from distributor Pioneer ; local agents Grundig Australia for Ministry of Sound or Bush receivers; or the local agent for Sangean receivers on (03) 9645 4700. In-car systems are available through Blaupunkt.