Digital Radios

Buying a Digital Radio

The Benefits of Digital Radio

Digital Audio Broadcasting (DAB) is a vast improvement over traditional FM radio, offering a clearer signal, greater choice of stations, easier setup and tuning, additional information and recording functionality. Each of these is more fully described below.

Clearer Signal

Whereas FM reception ranges for OK through to terrible, with hiss and other atmospheric interference, DAB is crystal clear at all times. Many of you will no doubt remember the transition from analogue to digital cellular phones - this is analogous to the improvement with DAB. The signal is either there and great - or not there at all. Most music stations broadcast at 128Kbps. This delivers quality similar to that of a standard MP3 file. Talk-only stations may broadcast at a lower bit rate, whereas classical music requires a still higher rate. As an example, BBC Radio 3 broadcasts at 192Kbps.

Greater Choice of Stations

Digital stations broadcast in groups known as ensembles or multiplexes. There are two UK multiplexes, BBC Digital Radio, which includes 12 stations, and Digital One, which offers eight commercial stations. Within each area there are then also local multiplexes with additional stations. Therefore, depending on where you live, you may be able to receive anything up to 60 stations, including some only available on digital radio. Digital One covers in excess of 85 per cent of the UK population, and the BBC multiplex addresses some 75 per cent.

Easier Setup and Tuning

When you turn on a digital radio, it automatically finds all the digital stations in your area, in a similar way to the auto-tune facility on modern video recorders. Stations are selected stations by name, rather than fiddling endlessly with a frequency knob. More sophisticated digital radios automatically sort the station names alphabetically. Many digital radios offer preset buttons, allowing you to go straight to your favourite station.

Additional Information

In addition to music and speech, digital radio stations are also able to broadcast text that can be displayed on the radio's screen. This varies by station and can include track and artist names, programme titles, contact details etc. The BBC is also developing an electronic programme guide.

Recording Functionality

Because the signal broadcast by digital radio stations is already compressed, it is simple to add recording functionality to digital radios. Some radios offer a pause/rewind facility, holding between 10 and 20 minutes of the current broadcast in memory. This allows you to use the Rewind button to listen to a news item or competition again or to pause the broadcast for the same period when the phone rings or the doorbell goes. All in all a similar approach to the live pause on Sky + boxes with which many of us are familiar. Some recording radios can store programmes on a memory card or stream them to an external device such as a MiniDisc or MP3 player.

Other Key Considerations

Simply stated, the cheaper the radio, the less functionality it will offer and the lower the sound quality. Economy models utilise lower quality sound reproduction circuitry and may, in some cases, also introduce a level of mains 'hum' at higher volumes. More expensive models will more faithfully reproduce the original broadcast and will offer some of the enhanced functionality described above such as station sorting, pause/rewind functionality, greater memory and thus recording time (which also enhances the pause/rewind capability), improved display screens etc.