Why are some digital radio stations mono?

Some digital radio listeners may have noticed that several stations are now broadcast in mono instead of stereo. For broadcasters it is a question of quality versus quantity.

On digital radio there is a finite amount of space available for the broadcast of radio stations. Currently demand for slots on digital radio means that the stations are able to use less of this space, which means reducing the audio quality to fit more stations in.

If you’ve ever ripped music from a CD for your MP3 player or smartphone you may have noticed that if you choose a lower bitrate the files are smaller and you can fit more in. It’s a decision between a smaller number of high quality recordings, or a larger number of songs at a reduced quality.

Digital radio broadcasters face a similar choice and have recently opted to increase choice on digital radio at the expense of the sound quality of the individual stations.

For example, KISSTORY and Planet Rock can both be on digital radio by broadcasting in mono. If a station like KISSTORY was in stereo there wouldn’t be space for another station like Planet Rock.

Some stations simply don’t need to be in stereo. There is little benefit to LBC or the BBC World Service of broadcasting in stereo or a higher bitrate when so much of their programming is mono thanks to their speech content.