People were originally encouraged to convert to DAB radios because, among other advantages, the sound quality would in theory be better.
However, the sound quality is now considered by many to be much worse than analogue transmissions. The reason for this is, by trying to squeeze more stations into a limited bandwidth, stations have had to reduce their bit rate and have sometimes changed from stereo to mono transmissions to do this.
Whilst stereo transmissions offer no obvious benefits to stations that concentrate on speech output such as news channels, they are necessary for music channels to give the best listening experience.
Stations now broadcast a mixture of mono, stereo and joint stereo (a compressed and more efficient way of transmitting stereo). Joint stereo is compressed to allow a lower bit rate, so it has worse sound quality.
DAB Stations that Broadcast in Stereo
BBC national stations are in mono where output is mainly speech and in joint stereo for Radio 1, 2, 3 and 6 Music. Radio 4 broadcasts a mixture of mono and stereo.
Of the national commercial stations, only Capital XTRA and Classic FM broadcast in joint stereo. However, some others — Forces Radio BFBS, Fun Kids UK, Jack Radio, Jazz FM Stereo, Magic Chilled and Union Jack — broadcast in DAB+ stereo.
London stations broadcasting in joint stereo include Absolute Radio, Capital London, Gold, Heart London, KISS, Magic London, Smooth London, BBC Radio London, Hits Radio, The Arrow and Matryoshka Radio. Most of the rest are mono apart from AsianFX Radio, Chris County, Nation Radio and 88.3 CENTREFORCE that broadcast in DAB+ stereo.
Across central Scotland, joint stereo is output by BBC RNanGaidheal, GO Radio Glasgow, Rocksport Radio, Scot Sun 80s, Scot Sun Gr8s and Scot Sun Hits.
A complete list of national stations broadcasting in mono and stereo can be found at DAB Assemblies Worldwide. There are, additionally, numerous local stations across the UK that broadcast in stereo. These can be identified at the local pages of DAB Assemblies Worldwide.