I've repeatedly expressed suspicion about DAB radio, and it seems that takeup is not what the industry hoped for. The BBC managed to cause a big spike in the 6music audience size by threatening to close the station - but then the bulk of that spike was DABless in the sense that the 6music online listening figures doubled compared against a year earlier (listening hours 642,734 in May 09; 1,384,216 in May 10), whereas RAJAR's figures (for a slightly different period since May 10 not available at time of writing) show the overall listening hours grew by around 75% - implying that the growth happened preferentially in online rather than DAB listening.
On Radio 4 there was some discussion today about whether someone buying a DAB radio today would expect it to last as long as a trusty FM radio that they've had for years. (Unfortunately the producers decided to drag the discussion out over multiple days so they only posed the question, claiming the answer will come tomorrow, bleh.)
This is something I hadn't particularly thought about - of course I know that DAB is not destined to last very long, due to various well-known factors such as inferiorities vs. FM, lack of DAB as standard in cars, and the growth of wifi and 3G - but then I remembered that the industry has even published a new improved version of the DAB format called DAB+. This was announced back in 2006, and even though it isn't currently in use in the UK and there don't seem to be any plans to do so, it seems odd to be stuck with an "old" version of the technology when the new one has already been in existence for years. Would you really go and buy a CD rewriter, now that there is not only DVD but also Blu-ray, and now that Apple has taught the big music industry players how to do downloads? What would be the point? It won't be too long before it's difficult/expensive to find blank CDs.
I'm not suggesting that the UK is likely to leap from DAB to DAB+ any time soon. But there are other countries using DAB+, and indeed there are other digital radio standards, and I'm concerned that we might end up stuck with the Betamax of the digital radio world.
So will our existing DAB radios work with DAB+? No. DAB+ is not backward-compatible with DAB, so if you're paranoid about the longevity of your radio then I suppose you'd need to check on the box and make sure that it says it does DAB+. (Frankly I wouldn't put a large bet on DAB+ either, I'd argue that a more generic medium like wireless internet is going to carry the radio of the future.) I went and checked the model of DAB radio that we bought our grandparents for Christmas not so long ago, and the answer is no. The rather reassuring and sturdy-looking design of the radio we bought them may be illusory.