Digital Radio, like Digital TV, enables more channels to be fitted into a smaller range of frequencies. To do this you have to be able to compress the information, which is done with a compression algorithm called AAC+. Australia is the first country to adopt this system, but other countries will no doubt follow. The resulting DAB+ is better than the previous DAB (as used in the UK) and British companies have been quick to produce radios which work with DAB+. Unfortunately the older DAB radios will not work with the new system, so those ones which were sold during the trials period are now useless apart from their FM capability.
Companies like Pure, Sangean, Arcam and Tivoli (as a group) give us a range of sizes and capabilities, from the smaller and simpler bedside clock/radio styles at $199 to the larger table or mantle units which can encompass DAB+, FM, and Internet Radio plus wireless streaming from your computer stored music. Some also have the iPod dock inbuilt, or can have one connected via an auxiliary input.Sangean and Arcam offer full hifi component sized tuners for those who want to add to their existing stereo or surround sound stack.
What about those fancy features?
While not all radios can do all the possible permutations of smart features, the list of possibilities is quite impressive. To begin with, you tune the radio by Autotune, where it scans in all the stations and their Identifications automatically and commits them to memory just like your television does. Tuning to a particular station is then simply a matter of scrolling through the list and clicking on the one you want.
Stations can then offer a crawling text line below the main display which might tell you latest news, weather, or traffic alerts. When a song is played, the title and artist can be shown on the screen. There’s potential to go to a full colour album cover display if (a) the station sends out the info, and (b) you get a radio with a colour screen that can show this. At present most displays are not in colour or high enough resolution to do this, but that side of things will develop over a few years, I expect.
Some radios have a buffer memory of around fifteen minutes, which means that you can Pause or Rewind what you have just heard – or just missed! You can resume listening in real time or continue to seamlessly listen a bit behind real time so you don’t miss anything else. This feature is not dependent on the broadcaster doing anything special, just on you having that option in your radio. An example is the Pure Evoke 2s, which is a full stereo radio and retails for $699.
The big winner in quality terms out of this exercise is AM radio. Developed after WW1, this method has some benefits in long distance coverage, but at the expense of being mono, somewhat compressed, and subject to electrical interference from all sorts of things. Now it is interference free, in glorious stereo, and close to CD quality.
Many of the DAB+ radios include the FM band as well. This is handy as not all the community FM stations will be able to move to the DAB+ band for a while yet. They also include clock/alarm functions in most cases, and the time is derived from the broadcast signal, so should remain very accurate!