DAB Report

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  • Gordon
    Full Member
    • Nov 2010
    • 1425

    DAB Report

    It's gone quiet around here lately so here is the latest on the DAB switchover project: there may be a Ministerial announcement in mid December. The CBA is yet to appear and is now well over 2 years late - that tells its own tale - and is now promised for a few weeks before the announcement. Believe it when you see it.

    OfCom have finalised their coverage plan to replicate FM and the cost is being assessed by DCMS and the relevant parties. I suspect that it is not a palatable number! It is that cost that will be the key point of whether the switchover will happen soon and will almost certainly delay it, possibly until 2020.
  • french frank
    Administrator/Moderator
    • Feb 2007
    • 30496

    #2
    Thanks for the update. Who produces the CBA - an independent body? Government?
    It isn't given us to know those rare moments when people are wide open and the lightest touch can wither or heal. A moment too late and we can never reach them any more in this world.

    Comment

    • Gordon
      Full Member
      • Nov 2010
      • 1425

      #3
      It is basically the job of the Treasury to define the rules and methodologies of all CBA studies done by and on behalf of government so that they are done systematically and consistently. In this case the economists are in DCMS using data provided from many sources - eg the SMMT in the case of radios fitted to cars. The methodology for this switchover CBA was published in July last year and caused a lot of debate!

      Comment

      • Eine Alpensinfonie
        Host
        • Nov 2010
        • 20575

        #4
        Originally posted by Gordon View Post
        ... and will almost certainly delay it, possibly until 2020.
        So presumably 7 years is long enough to ensure a decent digital broadcasting system can be set up.

        Comment

        • Bryn
          Banned
          • Mar 2007
          • 24688

          #5
          Originally posted by Eine Alpensinfonie View Post
          So presumably 7 years is long enough to ensure a decent digital broadcasting system can be set up.
          Long enough, maybe, but if, as appears to remain the case, they will be sticking with mp2 encoding, it will be pretty much good money chasing after bad. Every day a change to aac is put off diminishes the stimulus to 'upgrade' receiving equipment early (which upgrading helps the associated manufacturing sector). Dithering over a move to DAB+ only puts off the inevitable outrage from early adopters who shelled out on what will become obsolete DAB devices.

          Comment

          • Gordon
            Full Member
            • Nov 2010
            • 1425

            #6
            Originally posted by Eine Alpensinfonie View Post
            So presumably 7 years is long enough to ensure a decent digital broadcasting system can be set up.
            Yes, I guess so. I suspect that the cost of providing the FM "equivalence" is high and that there will be some sucking of teeth over it despite all the rhetoric so far. Why that should be so is a bit surprising because anyone with a bit of technical knowledge would have worked that one out long ago although could not put a specific number to it. I put the word "equivalence" in quotes because that is what is intended - not equality because it is technically not feasible for a number of reasons, some of them very complex - and setting the criteria for "equivalence" has been hard to agree as some of the OfCom documents published in the past have illustrated. These documents and a couple of consultations based on them have set the basis for the coverage plan that is being costed.

            Your use of the word "decent" is of course rather open for debate and so the resultant "FM equivalence" may be hotly debated. What is it that is being replicated? What is the specific definition of coverage?

            As far as my local DAB service is concerned it is already more than decent in terms of signal strength and coverage for reception on a portable receiver and exceeds by a significant margin the equivalent FM service here. That is because my local DAB transmitter is much nearer here than the FM for national BBC services. That experience will not be replicated everywhere.

            If the decision is made to proceed - AND a date for the start of switchover is specified, which may not appear in the December announcement - then it will take some time to complete the building of the transmitter network, time needed both to do all the building and also the cash flow needed to fund it. Some of the build out has already been happening and is in progress now of course but to achieve the final, complete network needs additional funds beyond what has been agreed so far.

            Any CBA should include a counterfactual analysis which looks at what else one could to with the money to provide a service by other means.

            Comment

            • Gordon
              Full Member
              • Nov 2010
              • 1425

              #7
              Originally posted by Bryn View Post
              Long enough, maybe, but if, as appears to remain the case, they will be sticking with mp2 encoding, it will be pretty much good money chasing after bad. Every day a change to aac is put off diminishes the stimulus to 'upgrade' receiving equipment early (which upgrading helps the associated manufacturing sector). Dithering over a move to DAB+ only puts off the inevitable outrage from early adopters who shelled out on what will become obsolete DAB devices.
              For switchover all receivers will be invited to be tested and if they meet a minimum specification will be given a Tick mark similar to the one used for TV switchover. Part of that spec is the requirement to include DAB+ decoding. Manufacturers may choose not to have their product tested in which case consumers should be wary of buying them because they may not work very well everywhere.

              At first the receiver manufacturers refused to agree to DAB+ based on arguments to do with patent licences for DAB+ among other things - the MP2 licences ran out last year and so they pay no more royalties on it. Yet they make DAB+ receivers for export. All the chip sets do the decoding in software anyway and so the matter is not to do with hardware at all. It is the broadcasters and regulators who do not seem to want to do DAB+ and that is partly to do with a transition which would need simulcasting for a time which they feel will be another cost. The other problem is that the spectrum to carry this simulcasting isn't there. A decision 10 or 15 years ago to go AAC would have resulted in the same problem and goes some way towards explaining why it has not happened. Coverage for DAB+ is marginally better than for DAB.

              We should remember that DAB, along with FM as it is implemented, is not an audiophile medium.

              Comment

              • Nevalti

                #8
                Originally posted by Gordon View Post
                For switchover .......... Part of that spec is the requirement to include DAB+ decoding. .....

                At first the receiver manufacturers refused to agree to DAB+ based on arguments to do with patent licences for DAB+ among other things ......

                We should remember that DAB, along with FM as it is implemented, is not an audiophile medium.
                That sounds promising news. What's the likelihood that DAB+ will be introduced before switch-over? Surely successive governments can't continue to tell the same lies and force-feed us with this awful, outdated system? There MUST be some politicians who actually have decent hearing and don't want us to be a 'third world' nation in terms of radio services. We have the worst digital radio system in the world!

                Are manufacturers actually selling DAB+ radios in the UK now? I tried to find one a couple of years ago but I could not. I rang 'Roberts' and 'Pure' who both said they had no plans to introduce them in the UK. Planned obsolescence I would guess!

                I agree that DAB & FM are not 'audiophile' but a reasonable quality FM receiver nevertheless produces a pleasant sound whereas MP2 based DAB is always hugely irritating. Fortunately there is no need to use DAB at home but, when driving, the FM signal is sometimes too poor to get acceptable reception. I switch over to DAB until the FM signal improves but it makes my ears bleed if I listen for more than a few minutes.

                Comment

                • Dave2002
                  Full Member
                  • Dec 2010
                  • 18039

                  #9
                  Originally posted by Nevalti View Post
                  That sounds promising news. What's the likelihood that DAB+ will be introduced before switch-over? Surely successive governments can't continue to tell the same lies and force-feed us with this awful, outdated system? There MUST be some politicians who actually have decent hearing and don't want us to be a 'third world' nation in terms of radio services. We have the worst digital radio system in the world!

                  Are manufacturers actually selling DAB+ radios in the UK now? I tried to find one a couple of years ago but I could not. I rang 'Roberts' and 'Pure' who both said they had no plans to introduce them in the UK. Planned obsolescence I would guess!

                  I agree that DAB & FM are not 'audiophile' but a reasonable quality FM receiver nevertheless produces a pleasant sound whereas MP2 based DAB is always hugely irritating. Fortunately there is no need to use DAB at home but, when driving, the FM signal is sometimes too poor to get acceptable reception. I switch over to DAB until the FM signal improves but it makes my ears bleed if I listen for more than a few minutes.
                  Re some of the "lies" about DAB, I suspect that some receivers/tuners are in fact DAB+, but not overtly so. Perhaps others could confirm or deny this. This would mean that if a move to (explicit) DAB+ or a newer version of DAB were to be made, that many users could still receive programmes, though early adopters, such as myself, who have a hard wired piece of kit would not.

                  Some current sets also have the possibility of software updates, and within reason this might be a way forward. Future sets could certainly have a degree of future proofing built in with the possibility of software updates. However, software updateable services are not always a good thing. Some earlier DVB kit became obsoleted due to changes in service, and I see frequent comments from others about "updates" on Sky services. Manufacturers and systems providers seem to think nothing of considering a lifespan of a modern device to be only a few years. I have a DVB set top box which I think was obsoleted because of an update, and has been put away in the loft or garage for some time now. I suspect it lasted only 4-5 years. I very much doubt that there was a hardware failure in the device. Against that, we have FM sets which are still functioning over 30 years after they were purchased.

                  Regarding service provision, the lack of allocated spectrum in the UK for DAB could present a problem for any shift towards DAB+ or similar, though there are strategies which could make a transition feasible, with perhaps only a short term requirement to either drop services or to use more RF spectrum.

                  The UK authorities have been somewhat dubious/duplicitous in their approaches to digital broadcasting, possibly due to technical ignorance by many**, and vested interests of a few, but there does indeed seem to have been a shift towards digital distribution by (mostly wired) networked services, so radio broadcasting may in fact be less important for some situations than a decade ago. Better quality audio can indeed now be provided by optical fibre networks, and high data rate Internet services, which are at least feasible in urban areas. However, rural and remote areas are still likely to be restricted to significantly lower quality services, either DAB - with the possibility of less than perfect coverage, or lower data rate Internet, or somewhat erratic mobile phone/device/3G/4G coverage.

                  ** I was very surprised to read an article recently by an MP (John Hemming - Liberal Democrat) - with much more technical detail - than I expected - he seems to know more about some aspects of DNS and ports than I do - but I think this was probably an exception which "proves" my rule that generally decision makers know very little about what they are deciding upon.

                  Comment

                  • Gordon
                    Full Member
                    • Nov 2010
                    • 1425

                    #10
                    Originally posted by Nevalti View Post
                    Are manufacturers actually selling DAB+ radios in the UK now?
                    Yes. I have a Sony receiver that has been available for many years although they have only recently begun to advertise that it is "DAB+ ready". Many receivers have to have a software upgrade to be DAB+ ready; some manufacturers put it in anyway and others want an upgrade fee from the consumer. So, pace Dave's remarks above, some of them see DAB+ as another way to soak the consumer for more money and a visit to a suitable "Upgrade Centre".

                    I rang 'Roberts' and 'Pure' who both said they had no plans to introduce them in the UK. Planned obsolescence I would guess!
                    Roberts are one of the refusniks; they hate DAB+. PURE are among the "good guys" so their "marketing" response is at odds with what their engineers tell me. Anyway neither of them make their own DAB+ modules!!!

                    .....when drive I switch over to DAB until the FM signal improves but it makes my ears bleed if I listen for more than a few minutes.
                    I cannot agree. That is not my experience. How can you judge sound quality at that level in a car? Nevertheless, your ears tell what you experience. Mine tell me otherwise. "Ears bleed" sounds to me like hyperbole. Sorry!

                    I am NOT a DAB fundamentalist either, just an engineer with 40 years' experience on analogue and digital broadcasting.

                    Comment

                    • Resurrection Man

                      #11
                      Originally posted by Gordon View Post
                      ......
                      Your use of the word "decent" is of course rather open for debate and so the resultant "FM equivalence" may be hotly debated. What is it that is being replicated? What is the specific definition of coverage?

                      ......
                      Excellent research, Gordon. I can;t put my finger on the exact document but do remember reading that Ofcom dropped the criteria for equivalence to be the same as FM mono which kind of explains Ofcom's resounding silence over the number of DAB stations that are currently broadcasting in mono !

                      Comment

                      • Resurrection Man

                        #12
                        Originally posted by Gordon View Post
                        .....

                        Any CBA should include a counterfactual analysis which looks at what else one could to with the money to provide a service by other means.
                        And I hope that it includes on the debit side the ยฃ56 MILLION they have set aside for 'marketing' any FM Switchoff. You could get an awful lot of new FM transmitters for that amount of money.

                        Comment

                        • Resurrection Man

                          #13
                          Originally posted by Gordon View Post
                          .....
                          We should remember that DAB, along with FM as it is implemented, is not an audiophile medium.
                          oooh..that's fighting talk

                          Comment

                          • Nevalti

                            #14
                            Originally posted by Gordon View Post
                            .....I cannot agree. That is not my experience. How can you judge sound quality at that level in a car? Nevertheless, your ears tell what you experience. Mine tell me otherwise. "Ears bleed" sounds to me like hyperbole. Sorry!

                            I am NOT a DAB fundamentalist either, just an engineer with 40 years' experience on analogue and digital broadcasting.
                            Hi. Yes, I have met a few other people who can't hear anything wrong with DAB. If you can't hear it, it will be difficult to explain. It simply sounds wrong and annoying. On top of that it isn't even in stereo half the time and of course the lack of benign compression makes quiet music simply disappear in the car unless you turn the volume up - then down - then up - then down - etc.

                            I don't understand the technicalities but I read somewhere, a few years back, that the testing regime, to compare the perceived quality of different codecs involved people listening for as long as they can before the music becomes annoying. Annoying! Is that how we are to judge digital music reproduction? Obviously some of us get annoyed rather earlier than others.

                            When it comes to listening in a quiet environment, we get almost the reverse situation. The low-level, subtle sounds are stripped away as 'noise' to allow the pathetic MP2 system to deliver 'stunning accuracy'. We can't even use DAB radios for talk radio dotted around the house/workplace like many of us do with FM - as all the DAB processors delay the sound to a different degree. The best you can hope for is an echo, more likely a cacophony.

                            I'm trying hard not to shoot the messenger - it's not your fault. I just hate the bloody things and the people who thrust them upon us.

                            Comment

                            • Dave2002
                              Full Member
                              • Dec 2010
                              • 18039

                              #15
                              Originally posted by Nevalti View Post
                              Hi. Yes, I have met a few other people who can't hear anything wrong with DAB. If you can't hear it, it will be difficult to explain. It simply sounds wrong and annoying. On top of that it isn't even in stereo half the time and of course the lack of benign compression makes quiet music simply disappear in the car unless you turn the volume up - then down - then up - then down - etc.
                              Hi Nevalti

                              I'm not quite sure if Gordon was suggesting he couldn't hear some of the deficiencies of DAB, though he may find it acceptable. I also think he might have been querying the suggestion that listening in a car was not ideal - it is not for FM either. Indeed, the car is a terrible place to listen to music, but for various reasons some of us do, and some of us may find that time in the car is the only time which works for us.

                              I'd say that at its best DAB is not too bad, and arguably with a good receiver it should be acceptable for most "cooking audio" purposes. Some people might find it actually unpleasant to listen to, though I think there can be many factors. Listening in a car may make audio unacceptable even on the very best equipment. However, there definitely was a time when DAB was unacceptable - bit rates below 192kbps are not good, particularly for serious music and the R3 DAB debacle years ago did seem to convince some that there was a problem.

                              If you have an appropriate car and radio, there should be settings to adjust the dynamic range/volume as the engine noise increases, though this of course may exacerbate the distortion problem. Some cars can do this for all audio inputs, and DAB sets should have settings which adjust the dynamic range. It might be a bonus if they are linked to the car amplification so as to push most of the signal above the background noise floor.

                              Re stereo in cars, this can be variable, and the position of the speakers is typically not ideal - either for the driver or anyone else.

                              I'll repeat Gordon again - neither FM nor DAB are high quality audio systems, and listening in cars is definitely not ideal.

                              Comment

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