In this article we’ll explain the difference between DAB and FM radio, and look at the pros and cons of each broadcasting medium.
FM and DAB are the two most popular radio broadcasting methods in the UK. Most of the country’s most popular stations, such as Radio 2 and Radio 4, are available on both FM and DAB.
FM stands for ‘Frequency Modulation’. It’s a type of analogue radio broadcasting that varies the frequency of the carrier wave rather than the amplitude. This makes it different to AM, which stands for ‘Amplitude Modulation’ and varies the amplitude of the carrier wave.
FM was invented in 1933 but wasn’t introduced in Britain until the 1950s. It took a while for FM to overtake AM in popularity, but by the 1990s it was the leading broadcasting method.
DAB stands for Digital Audio Broadcasting. It is a type of digital audio broadcasting that uses the MPEG-1 Audio Layer II audio codec, which is similar to the common MP3 digital audio format.
DAB was developed in the 1980s and introduced in the UK in 1995. DAB has grown steadily in popularity, and the majority of radios sold on the market now have a DAB receiver.
According to radio audience measurement company RAJAR, roughly 35.5% of live radio listening is done on DAB, compared to 46.6% on AM/FM (source). Despite the government’s support for DAB, analogue radio (AM/FM) still remains more popular among the public.
DAB vs. FM
Let’s take a look at the difference between these two broadcasting methods in more detail.
In theory, DAB can offer better sound quality than FM. In practice though, this often isn’t the case as digital radio broadcasts are compressed to allow several radio stations to broadcast using the same frequency.
The quality of digital audio is mainly determined by its bit rate, which is measured in kbps (kilobits per second).
However, things are a bit more complicated, as the encoding method also affects sound quality. For example, MP3 is a more efficient encoding method than MP2, so a 192 kbps MP3 file will sound about the same as a 224 kbps MP2 file.
DAB is broadcast using MP2, which is now an outdated audio format. DAB+, which is the newer standard of digital radio and is used on a few broadcasts in the UK, uses the superior AAC+ audio format.
DAB radio stations in the UK usually broadcast at 128 kbps or less using the MP2 codec, which means that they have lower audio quality than FM broadcasts. Furthermore, many DAB stations only broadcast in mono, or switch to mono at certain times.
Since FM radio is analogue, it doesn’t have a bit rate. However, if an FM signal were translated to a digital signal, it would normally be roughly the equivalent of an MP3 file at 128kbps.
DAB doesn’t suffer from the crackling or hissing you often get with AM and FM, but if your radio is in a weak signal area you might not pick the station you want to listen to, or the signal might cut out at frequent intervals. This is obviously very disappointing for those who buy a DAB radio expecting it to fix their signal issues.
There are also some things you can do to improve your digital radio signal.
On the plus side, digital radio isn’t affected by things like planes flying overhead that can affect FM signal, so provided you have a strong signal it should be consistent.
If you live in an area with relatively poor reception, your best bet might be to get an internet radio, as this will mean you don’t need to rely on radio reception.
Choice of radio stations
With an analogue radio, you’ll probably only have a choice of 10 or so stations on FM (unless you live in a big city). With DAB radio, however, you will have a much bigger choice.
For example, if you like rock music, DAB radio will usually let you listen to BBC 6 Music, Kerrang Radio, Arrow and XFM, among others.
If you like comedy or current affairs programmes you can pick up additional speech stations like Radio 4 Extra and LBC.
If you just want to listen to one of the regular stations an AM/FM radio will suit you fine, but in general DAB offers more choice.
Digital signals can transmit more information, such as the song being played. The technology also allows more stations to be broadcast in the same area, as they take up less frequency space than on FM and AM.
An analogy with television is to think of DAB as like Freeview, while FM and AM are like the old analogue channels. For a more complete explanation of DAB, see this article.
AM/FM radios used to be much cheaper than their DAB counterparts, but these days there isn’t much difference in price. If price is your only concern, you can pick up a basic AM/FM radio for £10 or so. However, there are lots of good budget DAB radios, so getting DAB doesn’t have to cost much more.
DAB radios are more likely to offer additional features such as Bluetooth than straightforward AM/FM radio.
If you just want something simple to listen to the radio, there are plenty of straightforward DAB radios without confusing additional features.
Ease of use
Some people are worried that DAB radios might be harder to use than AM/FM radios, but in fact they tend to be easier.
You no longer need to remember radio frequencies to find the stations you want; most DAB radios will automatically scan for stations and display them on an LCD screen, so you can just flick through to find the station you want.
Most digital radios also let you save your favourite stations so you can access them quickly. Best of all, you won’t have to fiddle with the frequency to get it just right, as the radio will scan and find the frequency for you.
Will AM/FM become obsolete?
The UK government have proposed a digital radio switchover at some point in the future, like the switchover to digital TV in 2012. However, an exact date or schedule hasn’t been set.
In a 2015 interview with the Independent, former culture minister Ed Vaizey said it will happen when over 50% of radio listening is digital and DAB coverage is comparable to FM coverage.
This criteria had been met by 2018, but in March 2018 the BBC said that FM radio would be kept to offer more listeners more choice.
AM and FM will probably be switched off at some point, but there’s no hurry to switch to DAB just yet. If and when AM/FM radio is eventually is switched off, it’s likely that online listening will have overtaken DAB anyway.
What about internet radios?
If you’re thinking about upgrading your AM/FM radio to get better sound quality and more stations, you might want to consider bypassing DAB radio altogether and instead buying an internet radio.
An internet radio looks like a regular radio, but instead of having an aerial it connects to the internet via WiFi or an ethernet cable.
Internet radios have a screen that lets you select radio stations, so they are easy to use and you don’t need to enter web addresses. As well as being able to pick up national and local UK stations, you’ll also be able to receive 20,000+ stations from around the world.
For more information, see this article: Is Internet Radio Better Than DAB?
Most radios on the market in 2019 offer both FM and DAB, so you don’t necessarily need to choose between them. DAB offers more stations to listen to, but generally lower audio quality.
For some more suggestions and help with choosing a DAB radio, see our roundup of the best DAB radios on the market.