I love DAB but it has problems:

  1. DAB tuning is slow. The receiver must collect data and spend 3+ seconds decoding before sound is output. Flipping through channels is annoying as opposed to FM. FM plays instantly.
  2. Multiple DAB radios simultaneously tuned to the same station results in unsychronized output. So forget about having radios in different rooms tuned to the same signal as you walk around the house (cleaning, throwing parties, etc). Also means a group of cyclists cannot simultaneously tune the same DAB station. FM is immune to this problem.
  3. Many stations share a single transmitter. When a signal goes bad for one station (e.g. bad weather), it’s also bad on ~20—30% of all other DAB stations. Many eggs in one basket.
  4. Weak DAB signals are intolerable. The sound cuts off and on repeatedly oscillating between silence and sound (as opposed to analog where there is a relatively steady amount of static that is often tolerable). E.g. In Brussels Bruzz on FM is decent but Bruzz on DAB rarely works. Some people report getting terrible DAB reception indoors.
  5. Vulnerable to Internet down time & cyber attacks, I suspect, because the DAB transmission tower likely sources its signals from the cloud.
  6. All receivers vulnerable to EMF pulses (thus solar events, nuclear war, and artificially generated EMF). No digital radios use vacuum tubes. Importance of functioning radio is greatly heightened in these scenarios.
  7. Most DAB radios do not feature manual tuning. And auto-tuning is unreliable. My current frustration is knowing that a good BBC4 signal reaches Brussels but none of my radios tune it. A Brussels retailer’s demo shelf had a DAB radio playing BBC4, but after auto-tuning the channel was lost.
  8. DAB probably does not work well in mountainous areas – unlike AM, which will likely be ditched with FM.
  9. Reduced range regional applications possibly complicated or non-viable. E.g. some airports transmit their announcements about flight delays/cancellations over a limited range AM radio which only tunes as you approach the airport.

When stations have both FM and DAB transmissions, you can quickly channel surf on FM. When something good is heard, you can then switch to the DAB version. Newer cars with DAB+ devices automatically switch between DAB and FM variations of the same station. They will lose this advantage when FM is gone.

FM can also seek in realtime. That is, it quickly finds the next strong signal at a given moment. With DAB, you apparently must run a scanning procedure in advance and that takes time. Then those stations are stored but signal quality can change from one hour to the next. Or if DAB can seek for the next station in realtime, I’ve not seen that on any of my radios. In DAB mode, the seek functions are gone.

  • evenwichtOP
    1·
    2 days ago

    well, I can just choose something that suits my tastes instead from the internet?

    I have no Internet, because the war on cash means there is tolerance for ISPs to effectively (and unlawfully) refuse to serve unbanked people. Being offline makes other info sources much more important. Unbanked people can get Internet but it’s a much higher price because only prepaid GSM providers are willing to take cash.

    (In practice, I would rather that we had more resilient mobile infrastructure, as more and more people have phones and can receive SMSs in an emergency; and more people getting into CB due to the possibility for bi-directional communication)

    Is that possible? SMS is notoriously unreliable. Sometimes I receive an SMS a full day after it was sent. Sometimes I never receive an SMS that someone is absolutely certain they sent. The tech seems to be inherently unreliable. Radio pagers from the 1980s are reliable. So it was foolish to ditch radio pagers, IMO. I wish I could buy a radio pager and subscribe. Some emergency response operations (firefighting and ambulance services) were smart enough to continue using radio pagers, but this service is not offered to the general public.

    Is there a technical requirement for the 3+ seconds of decoding before sound output? Or is this a matter of simply waiting for buffers to be filled before outputting?

    It’s a limitation of physics. No computer takes zero time to execute instructions. I don’t know to what extent buffering contributes to that, but it does not matter. You can’t really have a situation where all receivers are in sync with their decoding times. The only possibility would be to choose an easily achievable timespan, then mandate that all players add a delay. But this is borderline crazy talk. WRT point #1: given no legal interference, it would be possible for a radio to have several tuners so when someone is channel surfing, it could theoretically anticipate the need to give them the next signal in chronological sequence, to give an FM-like tuning experience.

    Your points about 1 and 7 really seem like a product issue more than a technology issue

    They are solvable issues, apart from point 4 (and realistically point 6 as well). That does not excuse a nationwide oppressive mandate to cut off FM transmissions and render all FM radio receivers as needless e-waste.

    Point 6 is not really the fault of DAB but instead of how the infrastructure is setup. FM transmitters could be source their data from the cloud too, and would be vulnerable to the same things.

    I would like to see the physical size difference between a vacuum tubes FM tuner and a DAB tuner. I doubt anyone will be making tubes DAB radios, but if they did there is a heck of a lot more complexity due to the AAC digital compression which must be replicated in analog circuits.