[...] og omreisende i foredrag James Cridland har sagt sitt om DAB og DAB+ med et spesielt fokus på Storbritannia, landet hvor DAB-utbyggingen har kommet lengst. Han slår [...]

(…this is a comment from RadioAssistant.com, which you’ll find in English here)

I’m curious, I’d not heard this before:
“[aacPlus HE v2 apparently removes the ‘bubbling mud’ noise that you might associate with a poor DAB signal”

I’d be interested to know how it does sound as it fails. There have got to be some artifacts… (otherwise we would be able to get away with lower bit rates) unless it just mutes completely sooner.

Also “MP2 (the ancestor to today’s MP3 format)” could be taken in the wrong way as they each have their strengths. Mp3 and AAC are very much a delivery system to take full quality audio and get it to the listener. Use audio that’s already been through a data reduction system as their input and they don’t sound very nice. MP2 however is a lot more tolerant to audio that has already been through data reduction algorithms, and is therefore still first choice for many uses even though mp3 and aac have been developed since.

I heard this at a radio conference earlier this week in Seoul, Korea. If I understood the speaker correctly, it is more error-resistant, but does mute quicker – i.e. no unpleasant digital crackles or bubbling mud. All the research I’ve seen seems to point to DAB+ signals reaching slightly further than DAB ones.

As I understand it DAB+ uses Reed-Solomon (RS) coding which makes the signal more robust (error-resistant) in a mobile situation. RS coding wasn’t included in the original DAB spec. – it was developed around 1993.

As I recall Channel 4′s application for the second UK multiplex (the one which was shelved) claimed that a switch to DAB+ would increase national coverage by about 2%.

Yes, when your committed to switching to ancestor (dinosaur is more apt) of digital formats it makes no sense to change, none at all. Unless you are starting from scratch, you must stay 30 years behind the rest of the world and be optimistic about the take up at all times.

Sorry James, nothing you can say will ever convince me that DAB is going to be a success and replace FM in the UK and one day someone like yourself will have to admit it.

I’ve looked at both sides of the argument before committing my opinion. The side you support is just pure wishful thinking.

I am firmly in the Grant Goddard camp.

Terry: You say “I am firmly in the Grant Goddard camp”… from where I’m sitting, Grant’s view is little more than someone shouting “rubbish! rubbish!” from a window at people in the street (though he does so with considerably more hard work!) What’s the future of radio, in your opinion, then? I’d be interested to know.

You also say “Sorry James, nothing you can say will ever convince me that DAB is going to be a success and replace FM in the UK and one day someone like yourself will have to admit it.” – well, back in July (here in the comments), someone like myself (me, actually) says “You pre-suppose that DAB is a replacement for FM. I’m not convinced: there’s little wrong with [FM] as a platform”. So that ‘one day’ was July 8th. I still believe it, too…

[...] Yep; very problematic. It won’t happen in the UK – at least, not until most sets in peoples’ homes are DAB+, I reckon. [...]

Okay James, In a couple of days I’ll write an appreciation of my views on the future of radio.

In the meantime this rather poignant graph from Google Trends provides some insight into the continuing interest in DAB searches for the UK.

DAB search trends

DAB/DAB+ (and DRM+) is designed to replace FM, sooner or later. The problem is that with actual bitrates of 128kbps Joint Stereo, public radio (BBC) can’t offer the same or more sound quality that is provided by FM.

I hope that it will be solved before digital switch-over, if it isn’t solved, I suppose that the audience will complain.

Here, there are higher bitrates: not below 160kbps. The problem is that there’s two exclusive stations only, the rest are simulcast. The coverage is scarce and a little number of DAB receivers has been sell.

I hope Spain will relaunch digital radio in 2011, on DAB+; and I hope that the minimum bitrate authorised for stereo stations will be 56kbps HE-AAC v2 (subchannel bitrate) to guarantee a “good” sound quality.

Hi James,

I would like to know why it is that people consider something to be a failure, yet it is currently in a third of all UK homes (and growing). Apart from lights, TV’s, telephones, washing machines, microwaves, cookers and fridges and maybe PC’s/laptops, what other appliances in the house have that kind of penetration and use?

I would also like to know why so many people believe and even have an undying love of DAB+++—++-@(to the power of three and squared again) or whatever it is that’s supposed to be superior to anything else – yet exceedingly few poeple own such devices, have ever accessed such devices nor even heard such devices and they certainly haven’t used one on the move in their cars.

Granted, we might be behind some countries that are now adopting digital radio (though the UK was the nation that developed it, so how are we “behind?”) – but that compares to Japan’s VCD to our DVD – we waited for DVD when we could have adopted the inferior VCD, to be on a level with Japan. As it just so happens, Japan have now ditched the VCD format and went over to blue-ray, by-passing the DVD – so they’re more advanced than everybody else again. It’s an unfortunate thing about technology, something better comes along fairly soon, how it might be adopted on a mass scale is dependent on various cirumstances – but slightly older technologies are not “failures” as a result, they just happened to be in that place at that time and were purchased accordingly.

As for DAB+ supposedly offering better audio quality and more services – most of our MUX’s are not full just now and I really do not believe that the commercial operators (and maybe the BBC) will give us any extra bits and bobs over and above the bare minimum than they can get away with providing, so it is highly likely that DAB+ will still have the same kind of audio quality for each station as DAB does just now.

As for FM supposedly having superior audio quality – get a grip folks. FM stations are heavily processed and compressed, to get above the noise floor and hiss (if you’re listening in stereo), as well as disguising the fact that FM on the move hisses and fizzes and flirts and flaps like a flag in a breeze when on the move, which is why the stations do that with their audio, so you don’t hear the crap in the background and the poor quality signal.

James, I’ve been back-and-forth mentally on whether I think DAB is a good thing or not. Fundamentally I think it’s a great idea. For me, where I live, it’s just not executed properly. We seem to be in a bizarre halfway house between a full rollout, or not. It’s clearly different from a digital TV upgrade, because we’ve not done it on a per-region basis – mostly because we don’t need to. However, anecdotally, from my house, I’m in full view of Bilsdale transmitter, yet I receive a very poor DAB signal whilst getting a great FM signal. I’m also a half-mile from Stray FM’s transmitter. The area I live in would probably count as ‘affluent’ and I imagine Currys/Dixons will have sold a boatload of DAB radios over the last few years. These people will probably suffer the same poor reception as I receive – and probably have their DAB radios switched to FM.

So what I’m saying is, unless there is serious gap-filling using the existing FM relay network, we’re not going to see the full scale flip to DAB because there are just too many gaps – and this will be especially apparent for in-car. By that time the internet may have ramped up sufficiently that users will have gone down the Internet Radio route.

When I am back in my native Harrogate I listen to the 23 national stations on DAB in the car but I have to tune to 97.2 to listen to Stray FM. Those of us in the original Stray team went for Harlow Hill as our transmitter site as the original Radio Authority approved site near Knaresborough would not give us the excellent coverage that the Harlow Hill site would and does give Stray FM.

I notice that the North Yorkshire local DAB multiplex plans to launch using both the Harlow Hill and Bilsdale sites. I feel that both Digital 1 and the BBC should add transmitters at Harlow Hill to improve coverage across that area of Yorkshire.

I agree with Stu Mitchell’s point about filling in the gaps of present DAB coverage at both national and local/regional multiplex level. I am pleased to see that NOW Digital have proposed to extend their Exeter/Torbay to North Devon. I hope that the talks over local DAB multiplex funding arrangements will allow for the finishing of the advertising of local DAB multiplexes e.g. Suffolk or Scottish Borders but that where there are still gaps in coverage e.g. West Shropshire or Norfolk (near the Wash) that the existing operator of the neighbouring multiplex will also wish to extend their coverage.

The roll-out of DAB to match existing FM national coverage would allow for the clearing of the existing 5 national FM stations from the FM band. This would allow for 88-108 MHz to be re-organised to cater for both local FM stations and community radio stations with improved transmitter power to properly cover their local areas, which are much smaller than the local DAB multiplex areas, in order that they can focus on their local audience.

DAB is probably great for those in the 6 main UK cities and surrounding areas – esp London and the South East where land is generally flat and transmitters are plenty.

I live in a particularly hilly area and DAB coverage is pretty much non existant and if you are lucky enough to get a signal it breaks up often with that dreadful bubbling mud sound. Sure FM crackles and pops but you can still listen to a weak fm signal.

Where do I live? 10 miles from Leeds so hardly in the wilds and still a rather heavily populated area. If I can’t get DAB then what chance have those in the sticks got? Apparantly DAB causes problems for local radio stations too.

DAB is an outdated, obsolete platform as can be seen by other Countries opting for DAB+. DAB was a case of change for changes sake.

Hi, Jimbob.

“Apparantly DAB causes problems for local radio stations too.” – given that they use completely different frequencies, how is this the case?

And how does DAB+ change any of the issues you have highlighted, which are all related to coverage?

Hi, I have a Roberts Radio MP-SOUND 53 which is a fine radio but its a DAB, and i live in Sydney Australia which i have since found out does not work, as it needs to be a DAB+ in Austalia, i have contacted Robert, to see, if i was to sent the Radio to them, could they modify it to a DAB+ they advised it can’t be done,would this be the case,as i find it very hard to belive they cannot modify to DAB+ as i paid 240 pounds for it to spend another 240 pounds seems a bit crazy,i would appriciate any advise/comments.
Roy

Hi, Roy. No, DAB+ cannot be retrospectively added to a DAB set: it requires a whole new chipset inside. Sorry about that. (Don’t know quite why I’m apologising, to be honest, but perhaps I’m doing that to be empathetic).

Presuming you’ve moved from the UK to Australia, I presume you’re also contacting the people who made your Freeview box and asked why it doesn’t work properly in Australia; and are also busily returning everything electrical to the retailer to ensure they replace the plugs… I’m afraid that continental standards are a fact of life everywhere these days.

Right, 48kbps AAC+ is not enough!

Also 128 kbps MP2 sound very very poor!!

But if you choose 112 kbps AAC+ it sounds very great!

So in a whole multiplex you could put 1-2 more stations and double the quality in the same time.

I bought a DAB+ radio in Australia last month. One guy in the shop (Dick Smith’s) said he bemoaned that he had bought a DAB radio in Egypt(?) and it wouldn’t play in Oz because it needed to be DAB+. The sales person said DAB+ would work in UK. The comments in the article include, “A DAB+ radio also will happily decode DAB…”. Well my new DAB+ radio (Sangean DPR 65) cannot find a DAB signal. I have a DAB radio (Panasonic) which does find a signal.
Are you sure a DAB+ radio will receive and decode DAB radio signals?
Is a DAB+ tuner less sensitive?
Is Weymouth, Dorset a particularly poor reception area?

Brendan: I am sure that a DAB+ radio will get DAB signals. I have one myself, bought in Australia, and it works just fine here.

A quick look at the ‘getdigitalradio.com’ website appears to show that if you stay at the Rembrandt Hotel in Weymouth, you’ll be able to get the national BBC and national commercial stations (no local ones though).

Different radios are less sensitive than others; it could be that your Sangean is a little deafer than the Panasonic that you have. I’d recommend going upstairs, sticking it on a windowledge, and running the auto-scan again. You ought to get those two multiplexes.