DAB+ and DAB – the differences, and its use in the UK

Having just bought a new digital radio I am sad it won't be able to receive the new radio stations being rolled out as has been the new multiplex from John macleod

Most modern DAB radios can also handle DAB+, but it's not been advertised because until recently, there was no DAB+ stations to receive in this country.

Fair comment Ian and thank you for replying from John macleod

James Cridland:

A DAB+ audio signal is encoded in aacPlus (strictly, aacPlus HE v2).

Not quite true James. It's only HE AAC v2 used for bitrates below 64kbps AND when Parametric Stereo is required.

HE AAC v1 is used for mono services with bitrates below 64kbps.

For bitrates of 64kbps and above LE AAC is used (because HE AAC offers no improvement in sound quality at higher bitrates).

Another point I would make is that whilst it is true DAB+ benefits from Reed Solomon error correction on top of Equal Error Protection, the improvement in coverage is marginal. So marginal, that in the real world the sensitivity of the radio being used makes more of a difference to the vast majority of listeners.

Really impressed by the quality of Jazz FM on D2. The fidelity of sound just stands out from anything else on D1 or D2!

Well I've studied FM, DAB, and DAB+ subjectively with headphones many many times, and my conclusion is simple: the new DAB+ transmissions at 32kbps and 64kbps (especially) 32kbps is a serious compromise. Both bit rates offer a 'hollow' and morphed stereo image, not remotely High Fidelity at all, sorry but it is true. When the BBC pump a non-compressed sound image through the network (or at least very high bit-rate digital signal), it simply blows away MP2 DAB @128kbps, although Radio 3's DAB @192kbps is good.

Long live FM until further notice!

PS - I can only see the bit rates of the improved DAB+ codec being brought down to the lowest tolerable levels to squeeze in as many stations in as possible!? So much for 'progress'.

Dear Eric I cannot get dab plus to work on my new digital radio but you explain in great detail what it should do I am only too disappointed that digital 2 is not in Scotland to experience the full effects of digital broadcasting at its bear or maybe worst depending on stations listened to from John macleod

Hello John Macleod, DAB+ transmissions may be a bit 'thin on the ground' at the moment nationally? Here in Staffordshire I can pick up a few, but only at a dire 32Kbps stereo, which is truly pathetic. An earlier test transmission in 2014/2015 offered just 64Kbps stereo, and again this was below par in quality. They may sound great from a distance or in mono, but once you listen and study the sound with headphones, you may begin to hear all sort of compromises, in particular it's like sound with a 'tunnel effect', and an inherent 'hollowness', it is quite alien in nature. Not surprising as the data-saving algorithms are complex which subtract harmonic content that we humans cannot apparently hear (using Fourier Transform analysis?) at source, and then this is knitted togther later. In essence, the lower the Tx bit-rate, the bigger the compromise. Ideally all DAB+ ought to be transmitted at 96Kbps stereo AND higher to make listening a pleasure.

DAB+ at 128Kbps and higher? ... I won't be holding my breath in the mean time John.

Dear Eric thank you for your quick reply to my message to you,as you rightly say dab plus is thin on the ground and I appreciate you telling me what transmissions are like in Staffordshire it's all but a question of wait and see or hear what may transpire in Scotland and many other parts of the UK by the way does the premise of 75 percent of the population getting digital 2still hold true or has this changed yours sincerely from John macleod

Hi John,

I know no more than you concerning any criteria for further DAB/DAB+ transmissions. As you may understand now, I am a bit of a audiophile, and currently the MP2 DAB codec is truly a regressive step, without question in fact. It has failed, but they (BBC especially) continue to flog adverts for us to buy DAB radios almost around the clock. Losing FM (if ever) would honestly be a regressive step, as they would cram in as many DAB stations they could on to the same MultiPleX.

regards
EJ

Dear Eric image heard and seen these adverts you speak of by the BBC,on another subject fm radio may well be switched off by 2020according to one or two sources in Inverness but if it does come off my only hope is that digital radio finally comes into its own in the way we hoped it could and would have from the outset but that's another matter for another time you sound as though your interest in the advancement of radio is diverse complex and highly knowledgeable all very much credit to you if you'll pardon any pun not intended with sincere good wishes to you from john macleod

I am not an audiophile and I am in middle age but the current DAB system to me sounds awful. I have listened to the new JazzFM Stereo output using DAB+ and often hear weird distortion particularly on vocals. The bit rates used are just too low. DAB is useless for quality and DAB+ if it is ever used in the UK would be used at the lowest bit rates possible. Money talks and if the multiplexes can squeeze more low quality audio in they will. Not impressed and have doubts about the future of broadcast radio.

Dear sir with media moguls as have done last week bought into a big radio company it doesn't look to good or in any way fortunate if the murdochs of this world continue to exist radio as it stands just now needs more of an injection that hurts those who listen to it because it's not being carried through in the way listeners of the platform would wish or hope for,yours sincerely from John macleod

Trevor Smith, If you crave for a high fidelity music experience, forget about DAB or DAB+... DAB is not an ideal platform for fireside listening!

Purchase an internet radio ''separate'' for your hifi or plug in a Revo Mondo set top device into the hifi auxilliary port. Tune in to online channels like Linn Jazz, a channel at 320kbps stereo (MP3) or catch Jazz on BBC Radio 3 at 320kbps AAC, giving audio reproduction akin to compact disc quality!
Due to financial cost, DAB+ will never, ever stream services at that calibre of sound!

Mainstream commercial channels on internet radio, generally use around 128kbps MP3 stereo, a sort of 160kbps stereo equivalent on the legacy DAB system.
Even at this lower data rate, sound quality is acoustically pleasing to most listeners!

You can escape from DAB at home, but more difficult to do that while in the car. Ongoing signal reliability for DAB+ on the road is currently far superior to reception offered on mobile broadband!

DAB is naff for inhouse entertainment!!

Willie what you say makes absolute sound sense to pardon any pun not intended and I would be first in the orderly queue to purchase one of the radio devices you mention in your message I think you understand implicitly everything about this spectrum of radio that others may never even touch the sides let alone allow their ears to appreciate the value of true enhancement of sound as it should be heard or am o lifted,if I state this case as knowing little and that you know more it is because you do,yours sincerely from John macleod

John, Thanks for the compliment!
To be honest, I am not an expert on radio, more of an enthusiast.
If the incumbent UK government defers a future announcement about a digital radio switch over date, the radio industry may require a rethink about DAB/DAB+ strategy!

Many thanks Willie, and also for further information relating to digital radio switchover which as an enthusiast which your good self is will one day look forward to it arriving, yours sincerely from John macleod

I just ordered a DAB+/ FM compliant radio. I am in Nigeria. Nigeria has digitalized it Radio Communication network. I do not know is the radio will be able to receive signals in my area. We have FM/ AM networks available here also. Can it also pick FM/AM signals? Any hope of it working here?

I just ordered a DAB+/ FM compliant radio. I am in Nigeria. Nigeria has digitalized it Radio Communication network. I do not know is the radio will be able to receive signals in my area. We have FM/ AM networks available here also. Can it also pick FM/AM signals? Any hope of it working here?