A Point Of Order for DAB Critics

By Art Grainger
Posted 28 September 2015, 5.32pm edt

I read a letter about DAB in a magazine (from someone who claimed to know a lot about the subject and had technical and radio background), which has prompted me to write this post. What astounded me was that despite the letter writer's supposed qualifications, some of the claims that he made about DAB were quite wild and, dare I say, a bit far from the truth.

However, he did have some points that I considered warranted some investigation.

One of his comments was that "many" stations on DAB are in mono. This is indeed true. However, he also suggested that this is a "backward step," for which I was left wondering if that was really the case.

So, with the use of an excel spreadsheet and whilst referring to the most up-to-date entries on the Wohnort website, I decided to see how far "backward" has DAB actually gone.

So here's the maths.

Excluding the trial mini-MUX's, there are currently 159 of the UK's national and local FM stations broadcasting on DAB. Most of them are broadcast in stereo, with the exception of 24 services (around 15%). Those stations are:-

Angel Radio (aka Angel Digital), BFBS (Brize Norton), Bob FM, Bridge FM, Central FM, Citytalk, Connect FM, Fire Radio, Jack FM (Surrey), Jack FM (Berkshire), Kiss, LBC, Magic, MKFM, NECR, Pulse, Q Radio, Radio Essex, Radio X, Smooth Radio (East Midlands), Sunrise Radio (Bradford), Trax FM, Waves Radio and Wirral Radio.

That might look, at face value, to be quite a lot. However, included in that list are a few London stations, community stations and several small-scale stations. Whilst it's disappointing that they broadcast in mono on DAB whilst being available in stereo on FM, the truth is that almost all of those stations broadcast to a much smaller area in super stereophonic sound on the VHF band, often with a low powered transmitter. By broadcasting on DAB, albeit in mono, they are actually enlarging their service area quite considerably - or in the case of the London stations, going across the UK. In the case of Central FM, it may be available in stereo within reach of its FM signal but for many commuters who live in its area but work in Glasgow or Edinburgh, DAB provides the means for continued listening, whereas Central FM has virtually no FM signal in Glasgow and a patchy signal in some parts of Edinburgh. Therefore is being in mono on the Central Scotland multiplex a backward step?

Indeed, for all of the stations in the above list, only Citytalk (an intended speech service) and Smooth Radio on the Birmingham multiplex (only) appear to have gone "backwards" on DAB, whilst the rest have extended their service areas by being on DAB, even if they have chosen to be in mono.

Of course, there are some services who are broadcasting to larger areas by being on DAB, albeit in stereo:- Minster FM, Stray FM, Yorkshire Coast Radio, Compass FM, Capital Xtra, Smooth Radio (Scotland) and Juice FM (Liverpool).

How about medium wave and long wave stations?

Well, all AM stations in the UK broadcast in mono - they can't help it. So it would be quite a forward step if they broadcast in stereo on DAB, right? Let's see.

Excluding LP-AM services or AM-op-outs from BBC local stations, there are 53 AM-only stations in the UK. Most of them do indeed broadcast in stereo on DAB (the Bauer "2" stations, the Gold and Smooth stations and UTV's local AM stations). That leaves only Absolute Radio and Free Radio 80's as music services remaining in mono. LBC London News, Radio 4 LW, Radio 5 and Talksport are speech services, whilst Asian Sound, Lyca Radio, Lyca Dil Se, Panjab Radio, Radio XL, Sabras Sound, Sunrise Radio and Spectrum Radio have decided to remain in mono for the ethnic communities they serve.

What about those services that are only available on digital platforms and are not available on FM or AM anywhere in the UK?

Well, this is where it can be easily claimed that "many" stations are in mono on DAB. There are 62 services that are unique to DAB (and other digital platforms), some nationally. However, only 6 have chosen to be in stereo:- BBC 6 Music, Dee On DAB, Eagle 3, Pirate Oldies, The Arrow and Triple Hits.

Again, whilst it's disappointing that the remaining 56 services that are unique to DAB are in mono, is it a backward step? We probably wouldn't have those stations at all if DAB didn't exist and we were stuck with having only analogue platforms due to the lack of frequencies. Also, would it have been financially viable for some services to able to broadcast in stereo? I know I prefer to have choice, even if it meant that stereo was sacrificed to make it possible. I really enjoyed TeamRock.

So, there's the seed of a subject that has many thorns for some people. In my next post I will compare the bit rates of stations on DAB that are also available on satellite and Freeview.


4 years, 7 months ago

Thanks for the facts and figures about DAB, but the world has moved on for most DAB critics! DAB is not a near-monolith for digital radio anymore, there is other & better ways to listen to favourite digital radio stations.

DAB is okay for the low end mid-fidelity audio market, but has current limitations for anything else. Mono or stereo on DAB, who now cares?

4 years, 7 months ago

As promised I did some more research. This time I focused on the differences between those stations on DAB that also broadcast on Freeview and/or satellite.

DAB is often criticised for the "many" stations that broadcast in mono and at low bitrates. It has even been described as being a platform that is "backward" for those reasons. Yet satellite and Freeview is rarely criticised for the quality of sound for the radio stations on there.

Why is that?

Is Freeview and Satellite offering better quality or more stations with stereo as opposed to DAB broadcasting in mono?

Could it be because there are so few people who actually bother to wire up their Freeview or satellite system to a hi-fi system to enjoy the supposedly better sound quality (I'm one of them, by the way)?

Or is it because finding technical information about radio stations on the digital TV platforms is actually fairly hard to find, whereas DAB information can be found with relative ease? Surely all these audio critics aren't living in blissful ignorance? After all, I had to get the information from a French website after a lot of googling.

Maybe they are living in ignorance - because here are my findings.

The stations that broadcast in stereo on DAB and also broadcast in stereo on Freeview and/or satellite are:-

BBC Radios 1, 2, 3, 4 and 6 Music, as well as BBC Radio Scotland, BBC Radio Wales, BBC Radio Ulster, BBC 1 Xtra, BBC Radio Cymru, BBC Radio Nan Geal and BBC London (although BBC London broadcasts in mono on Freeview). The commercial stations are Capital, Capital Xtra, Classic FM, Heart, Gold and The Arrow.

The stations that broadcast in mono on DAB and also broadcast only in mono on Freeview and/or satellite are:-

BBC Radio 5 Live, BBC 5 Live Sports Extra, BBC 4 LW, BBC World Service, Premier Radio, Talksport, LBC News.

As you would expect, those stations are speech services, so it would be pointless for them to be in stereo - but what about the music services?

Well, there's a substantial list of them, which might surprise some people. The following music stations prove that neither Freeview or satellite offer anything better than DAB because they are not available in stereo on those other two platforms either:-

Kiss, Magic, Planet Rock, Kiss Fresh, Kisstory, Heat, The Hits, Kerrang, Absolute Classic Rock and Absolute 90's.

Are there any services that broadcast in mono on DAB but broadcast in stereo on Freeview?

Yes, those are BBC 4 Extra, BBC Asian Network and Absolute Radio.

It makes sense for those stations to be available in stereo for at home listening. A proper TV aerial pointed to the transmitter would offer the best reception. Those stations are also available on satellite in stereo.

Two stations that broadcast in mono on DAB are also only available in mono on Freeview but can be heard in stereo on satellite:-

LBC and Smooth Extra. Strangely, one of them is a speech service.

These stations are not available on Freeview but they do broadcast in stereo on satellite whilst being available only as mono on DAB:-

BFBS, Radio X, Panjab Radio, Absolute 70's, Absolute 80's and Jazz FM.

4 years, 7 months ago

The majority of radio stations on DAB, for any listener, are in mono. That's the only real fact that matters.

I wrote a big blog post about Radio X being in mono, but decided not to publish. But from it, the most salient section: that there are no plans to fix this. This bit is the most frustrating part to me.

DAB+ is the potential solution to all this: an improved audio encoding technology which gives good-sounding stereo at 64kbps or even lower bitrates. It's in use in almost every other country that uses DAB; but not here. Nevertheless, most sets sold in the UK cope with it - look for the 'Digital Radio' tickmark, the Digital Radio Plus logo in devices sourced from Australia, or the DAB+ logo elsewhere.

The BBC have no plans to do anything with DAB+, cautious about scaring listeners away from purchasing a new set.

Digital One, the existing commercial digital multiplex, is all in mono apart from Classic FM and Capital Xtra. Every other service is in mono.

Sound Digital, the new digital multiplex coming on-air next year, doesn't have a single service in stereo. Their plans, which won them their Ofcom licence, promised just one DAB+ service (which might be stereo), but they still have yet to announce what it is.

There are no DAB+ services broadcasting on any DAB multiplexes in the UK right now; not even on the trial multiplexes that Ofcom themselves are providing technical support for. As far as I can ascertain, DAB+ services don't even count as "audio" under current Ofcom regulations.

Now - let's be clear. I'd much rather have Radio X, or Radio 4 Extra, or Fun Kids, or Absolute 80s in mono than to not have them at all. The point isn't that mono radio has no place on-air: it clearly does. But if it isn't ideal - and everyone in the industry agrees it isn't ideal - why don't we have a plan to fix it?

The industry attitude appears to be "pile it high, broadcast it cheap" with no plans to reverse out of a decision that could mean enforced FM switchoff in favour of a system only broadcasting mono. And that's not good.

4 years, 7 months ago

Okay. In my area, excluding speech services, I have 16 DAB stations in stereo. This includes all of the FM services in my area, plus a handful of DAB only services.

There are 19 mono (music) services in my area. All of those stations are either unique to DAB or they are stations broadcasting on FM somewhere else. Either way, I would not have had the extra choice. So is it a backward step?

Also, almost all of those mono services are also only available in mono on Freeview or satellite - but nobody seems to slate those two platforms for it. Isn't that strange?

4 years, 7 months ago

That's my argument too - that it is not a backwards step having more choice. It is a backwards step if it reduces the choice of stereo services when FM is switched off. It is disappointing that there is no plan to fix it.

4 years, 7 months ago

When I used to listen to satellite radio on Sky Digital with audio pick up through hifi speakers, the primary music services from BBC and RTE were all at 160/192 kbps with discrete stereo separation. I am positive that Planet Rock, along with (now defunct) PrimeTime Radio had datarates around 192 kbps, creating a pleasant listening experience, back then.
The BBC regional radio on satellite was definitely inferior to FM stereo. The (now defunct) ONEWORD book channel had poor audio, producing lispy voices. So, satellite radio did/does indeed include some mediocre audio quality channels.

I checked the Sky EPG radio list recently, actual channel quantity is on the wane. So, this could be an indication that listeners are moving elsewhere. -or- The EPG costs are becoming prohibitive for some broadcasters!

Perhaps, most viewers who listen to the radio on a satellite tv system are not hooked up to a hifi for best audio results. Listeners in turn, may be ''deaf'' to the variations of audio quality on selected channels!

If the Republic Of Ireland eventually decides to take the DAB+ route, the UK could be the last country standing with a DAB MP2 compression layer. Sky Digital are considering dumping MP2 in the not-too-distant-future and it is indicated that Freeview could also dump MP2 around 2019. DAB MP2 technology will be really ancient in the 2020s!!

4 years, 7 months ago

Surely nowhere near as ancient than LW & MW are now. Heck, I find it weird that people think of DAB as outdated, when it hasn't been around even as long as FM, never mind MW, LW & SW.

4 years, 7 months ago

Ian, I agree with your sentiment, but digital computer technology can progress a lot quicker than its predecessor analogue.
Away from DAB, even the early versions of some internet digital (eradio) tuners may now struggle to decode some channels on newer encoder formats like AAC.
Digital terrestrial television switch over happened a couple of years ago. A 2nd switchover is expected by year 2020 to discontinue MP2 transmission. The grass is not being allowed to grow under anyone's feet in the digital age!

Generally, DAB enthusiasts love their technology, a bit like old time rail buffs polishing their steam locomotives with great affection!
The reality is, DAB is a platform to deliver radio services and that's about it...
PS: I used to love shortwave radio, but it is no match for the iPod/iPad generation, unfortunately. Perhaps I'm a steam radio fan after all!

4 years, 7 months ago

Willie, it's not sentiment, it's fact. It's like saying we should have closed MPEG2 Digital TV, before closing 625 line analogue TV, or indeed 405 line analogue TV, because we now have MPEG4, it makes no sense. And your comparing DAB enthusiasts to steam train enthusiasts makes no sense either. A more blatant case of apples and oranges I've not seen.

There's no compelling argument for shutting down DAB, before shutting down LW, MW, SW or FM, and even then, I would suggest replacing them with DRM, to work alongside DAB & DAB+.

4 years, 7 months ago

Ian, DAB is nowhere near the digital arcadia! DAB+ (MP4) is the means of getting there, I think.
The 2020s should see radio with pictures as mainstream consumption. Digital radio on tablets & smart phones with pictures is currently a prelude act as we move towards that era!
I sincerely believe analogue radio will die out by the end of this decade..

4 years, 7 months ago

Willie, be careful with the term MP2 and MP4 you are throwing about.

MP2 is MPEG1 Layer 2. That's the format we use for DAB in this country.

MPEG2 is the format that we use for the majority of standard definition TV broadcasting.

MP2 and MPEG2 are not the same thing!

DAB+ is MPEG4 HE-AAC v2, the format of HD DTT broadcasts is MPEG-4 AVC High Profile Level 4

Hope this helps.

4 years, 7 months ago

Willie, digital arcadia??? Nobody bloody cares about some fictional idea of a digital utopia!

If you're going to insist that DAB is out of date and should be switched off, then you need to say the same for FM and AM transmissions, as by comparison, they are museum pieces.

Get out of your fantasy utopia, and deal with what's real. DAB isn't likely to disappear before 2030, at the very earliest, and considering that community radio will soon be joining DAB after the small scale trials are done, then you can push that out to somewhere near 2050.

4 years, 7 months ago

Ash Elford, thanks for that feedback.

Ian, I worked for a computer company through the late 70s to 2002. I did a spot of computer production before ending up latterly in their quality engineering department.
During the early years, we manufactured monsters of computers with heavy storage devices, holding (which now can be described as) modest capacity. It took two people to lift a drive out of a box and on to a trolley jack, then hoisted up to place and secure on sliding chassis tracks within a tall cabinet. An equivalent amount of storage capacity can now be placed on the palm of your hand. -Not Fantasy!
Ironically, all offices at my work were equiped with state of the art typewriters, manufactured by a main competitor at that time. We soon learned, these solid state typewriters were on borrowed time and in the end became museum pieces in the digital age. -Not Fantasy!

Now the talk is about driverless taxis, cars and buzz of a Google postal service by using drones. The latter may require a highly regulated logistics plan. -Not Fantasy!

Ian, to sum things up, anything goes in the computer age, digital technology will not stop for anyone!
Incidentally, DAB+ is compatible to ride over the original DAB transmission system currently in place. DAB as a technology in the real sense will not close, it will be upgraded!

4 years, 7 months ago

Willie Bone...

Ian, I worked for a computer company through the late 70s to 2002...

Yeah, all that does is confirm you're so sucked in to the tech bubble, that you don't know what happens outside that bubble, in the real world. Technology is only a tool, not an end.

And teach grandma to suck eggs. My first computer had 8K of memory. Now you get computers with 8gigs of memory. We know all that, yada yada yada.

But the newness of technology does not define what trends. If that were the case, why would vinyl records be growing in popularity again? It's product that defines success, not the tech. Hell, FM is about 75 years old, and it's still popular today.

DAB is going to be around for a while yet.

4 years, 7 months ago

For once I agree with Ian, vanilla DAB is going nowhere, although as been mentioned ad nauseam, we should be moving to AAC+ and yet we're not doing nothing.

Another tv switchover which may mean DTT viewers moving fully to DVB-T2 will be a doddle thanks to viewers buying new HD sets or set-top boxes, while in radio, we still have analogue receivers that are many years old and first gen DAB only receivers which I suspect the consumer won't replace as it "does the job" of providing the station they wish to listen to.

4 years, 7 months ago

Indeed. I care very little about commercial jingle stations that play the occasional song in between broadcasting in mono or stereo. I care a lot about (vanilla) DAB giving me rock solid reception for the BBC, which is not something I get with FM.

4 years, 7 months ago

Art, Why drink water when you could sip champagne? We should be moving forward with DAB+ like everyone else in the European continent with Ireland (currently) being the exception.

Let vinyl and choo choo train enthusiasts have their fun with their legacy outfits. Even keep DAB along with DAB+ for the people who cherish 'vanilla'! The radio industry has outgrown the original DAB system with no one to blame. Remember, DAB was originally expected to carry no more than around 30 services back in the 1990s.

DAB does work well with certain limitations. It is now akin to electrifying a national railway network by using 750v DC on the 3rd rail or using 1500v DC overhead wires. These old methods work reasonably well, but would never be adopted for heavy rail use anymore.
As stated previously, the good news for DAB infrastructure is, the hardware is future proofed to enhance DAB+.

I always recommend to friends to purchase internet digital radio with an embedded DAB+ decoder for back up.
DAB+, bring it on!!!

4 years, 7 months ago

Actually Willie, it's 25,000 volts AC for overhead power lines on railways. 1500v DC was used for trams. 750v DC third rail systems are still in heavy use throughout the south-east of England, especially London, as well as local underground systems in other cities, simply because of the practicality of putting down a third rail, as opposed to considerable architectural engineering that would have to be involved in placing overhead wires, not to mention the high levels of rolling stock in one of Europe's busiest cities that would need to be replaced or modified.

I'm not supporting vanilla DAB exclusively, I don't know why you have that impression. I support DAB as a platform because it has proven to me to be the only platform where I can go for very, very long journeys, even into mountainous areas, deep valleys, forests and so on and I never lose the signal or suffer from the kind of interference and audio distortions that I get on FM and AM.

Of course, I'm tuned to the BBC for most of that but even some local commercial radio multiplexes offer considerably better reception than the equivalent output on FM.

Listening to radio via smartphone in the car is great for the motorways, trunk roads and urban areas but (especially in Scotland) drive away from those and you're back to 2G.

The point I tried to make in this thread is that DAB critics complain about "many" stations being in mono on DAB - yet they don't seem to have noticed (nor complained about) the same stations only being in mono on Freeview, cable or satellite, even though 2 out of 3 of those other platforms allow broadcasters a wee bit more bandwidth to offer stereo

Only on Planet Radio Forum do you get people slating DAB for stations being in mono, yet they go absolutely beside themselves at the slightest prospect of a radio station named after a 60's pirate and still "broadcasting" from a boat being available on medium wave .... sometime, maybe, perhaps, if OfCom makes an exception because of who they are and so on.

4 years, 7 months ago

Art, the slightly off topic of rail electrification: The modern standard of rail electrification is indeed 25k volts AC overhead catenary now being deployed on HEAVY railways, everywhere. Incidentally, Merseyrail also have a 3rd rail surface railway.
1500v DC overhead wires are still used in the Netherlands and in Melbourne & Sydney, Australia. The early version of these overhead systems were deployed in an era when AC was still an unknown entity. The voltage on these old systems are too low for heavy freight duties, higher powered EMUs and stuck with a 100mph speed limit (on 3rd rail). The transmission systems for DC are costly requiring many feeder stations & very thick overhead catenary.
I am aware of light rail on 750v DC overhead with the Glasgow subway energised by 3rd rail 640v DC.
The point is, these older systems work well like original DAB, but with limitations..

4 years, 7 months ago

Art, I agree with you about the quality of signal reception on DAB. Nearly a decade ago, I worked in rural South Ayrshire villages within the Carrick hills.
Whilst driving, DAB reception on (what was then) the Score Digital Ayr multiplex was excellent for BBC Radio Scotland, Westsound, West FM and 'The Storm'. FM radio reception was extremely poor in the area. (The local multiplex will see a relay opening up for the nearby Girvan valley in the next few months).
DAB's quality of signal reception is appreciated in Ayrshire, especially south of Kilmarnock in an area that can only be described as ''mush'' reception on AM.
DAB actually brought all FM & AM services under the one umbrella, bereft of co-channel interference or multipath distortion.

I mentioned on a past thread that DAB in Northern Ireland actually enhanced signal reception throughout the north.

If you are referring to a Radio Caroline aspiration of opening up a medium wave service for output, I personally think it will have short term novel value on a nostalgia ticket! Radio Caroline's dedicated staff are better to use the money elsewhere!
I occasionally dip in to Radio Caroline with its album tracks, better heard at 128kbps (MP3) stereo on internet digital radio. -Rock music like classical
music requires stereo separation to give the music respect!

4 years, 7 months ago

I was driving around the very lower part of South Ayrshire and Dumfries & Galloway, around places like Straiton, Barr, Barrhill, Glenwhilly, New Luce and quite deep into the hills and thick forest plantations. FM was just a shambles but DAB was rock solid.

Did I care that it wasn't quadraphonic surround sound on DAB+++--+-+ ? I Couldn't have given a monkeys .... I was too busy listening to the program content with great reception.

4 years, 7 months ago

Better still, take the train on the picturesque Galloway Line, relax & really enjoy the scenery as the train snakes its way through some of the places you mentioned.

The binaural and quadraphonic appreciation societies have less members than Ayr United Football Club!

4 years, 7 months ago

Indeed. I actually have Madonna's Immaculate Collection, Paula Abdul's Spellbound and Sophie B Hawkin's Whaler - all of which were recorded as Q-Sound. Absolutely everybody I have told that to didn't even know what it was, nor did they notice any difference between it or any other stereo recording.

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