Why is digital radio so bad?
Discussion
When we were told the analogue system was to be shut down the government and their boffins all said it would boost the digital system, but, to date since the switch off I must say I have seen little improvement.
Granted, my radio is inside a walled building but an FM signal can penetrate so why can’t the ‘oh so brilliant’ digital signal? I am sick of listening to radio stations that sound like their being broadcast from a swimming pool or don’t broadcast at all!
Are there any further improvements on the way or is this the best it will be?
Granted, my radio is inside a walled building but an FM signal can penetrate so why can’t the ‘oh so brilliant’ digital signal? I am sick of listening to radio stations that sound like their being broadcast from a swimming pool or don’t broadcast at all!
Are there any further improvements on the way or is this the best it will be?
Lots of stuff out there on this. Firstly coverage is not that fantastic. FM evolved from AM and as such had a reasonable baseline to build on. DAB was a fresh start and it's range seems to be more limited along with the power required to transmit and receive is a lot higher as well. Because of this the Broadcasting company responsible did not set up as many aerials to broadcast it, hence coverage is patchy outside of cities.
Secondly the BBC and the authority concerned used a Codec for digital encoding that was already out of date when it was proposed. The MPEG2 Audio level 2 format is not used by anything else. Coupled with cramming stations on to the available bandwidth left the signal pretty degraded. It currently runs at BELOW MP3 standards on many stations leaving them sounding pretty rough. It some places the commercial stations and BBC vocal broadcasts are in Mono as they "save" the bandwidth for other stations. The problem is to get the sound quality they need to transmit at 256 k/bits/s with 192 k/bits/s being "acceptable". Most stations do transmit at this rate. However to get more stations in some drop to 128 k/bits/s and even 64 k/bits/s which basically is Mono transmission. It's that bad nobody else has taken the system up and Denmark scrapped it to start again. DAB2 uses a different CODEC, the HE-AAC version of the AAC codec. This allows a more robust signal, and allows more stations to operate without losing quality. Essentially 64K/bits/s HE-AAC gives a signal as good as 256 K/Bits/s under MP2. This allows the stations to be "crammed" in without losing listeners.
Secondly the BBC and the authority concerned used a Codec for digital encoding that was already out of date when it was proposed. The MPEG2 Audio level 2 format is not used by anything else. Coupled with cramming stations on to the available bandwidth left the signal pretty degraded. It currently runs at BELOW MP3 standards on many stations leaving them sounding pretty rough. It some places the commercial stations and BBC vocal broadcasts are in Mono as they "save" the bandwidth for other stations. The problem is to get the sound quality they need to transmit at 256 k/bits/s with 192 k/bits/s being "acceptable". Most stations do transmit at this rate. However to get more stations in some drop to 128 k/bits/s and even 64 k/bits/s which basically is Mono transmission. It's that bad nobody else has taken the system up and Denmark scrapped it to start again. DAB2 uses a different CODEC, the HE-AAC version of the AAC codec. This allows a more robust signal, and allows more stations to operate without losing quality. Essentially 64K/bits/s HE-AAC gives a signal as good as 256 K/Bits/s under MP2. This allows the stations to be "crammed" in without losing listeners.
Interesting this, I was given a DAB radio (arelatively expensive Pure radio) a few years back and I had the same issues as reported above. Anything that wasn't a major station got awful reception. It stopped being used when a) I could run my TV through an ipod dock in the kitchen - and also get digital radio, and b) when I could stream internet radio through my ipod.
I'm peed off with this because like a poster above says a little FM radio would be just the job.
I read somewhere that the DAB transmissions would be "turned up" at switchover, and I really hope they are, as I can imagine that driving around with a DAB car radio will be a totally s
t experience.
I'm peed off with this because like a poster above says a little FM radio would be just the job.
I read somewhere that the DAB transmissions would be "turned up" at switchover, and I really hope they are, as I can imagine that driving around with a DAB car radio will be a totally s
t experience.Just on that - you can't have "awful reception" with digital. By definition it's a 1 or a 0 so unlike FM you either get the signal or you don't. If you're hearing poor quality then it's being broadcast at poor quality.
Interesting that people are having issues because although I knew DAB was of a lower quality than FM, I thought pretty much everyone could get it without issue in the UK (assuming all the above are in the UK). I was even considering getting it for my car but I think I'll wait now
So this raises a question: since internet radio is even better (vastly more stations and a choice of quality) and wifi is becoming ever quicker and more prevalent, will DAB be superceded by wifi-based internet radio before it has the chance to establish itself...?
Interesting that people are having issues because although I knew DAB was of a lower quality than FM, I thought pretty much everyone could get it without issue in the UK (assuming all the above are in the UK). I was even considering getting it for my car but I think I'll wait now
So this raises a question: since internet radio is even better (vastly more stations and a choice of quality) and wifi is becoming ever quicker and more prevalent, will DAB be superceded by wifi-based internet radio before it has the chance to establish itself...?
We should be using satellite radio by now. It's crazy we're still fanning around with ground based transmitters, when the obvious place for a transmitter is above our heads!
Granted the signal can't penetrate buildings (neither can DAB very well), but it's a small price to pay for a better signal when out and about.
Granted the signal can't penetrate buildings (neither can DAB very well), but it's a small price to pay for a better signal when out and about.
prand said:
...
I read somewhere that the DAB transmissions would be "turned up" at switchover, and I really hope they are, as I can imagine that driving around with a DAB car radio will be a totally st experience.
Even better is that no two countries can agree on a DAB standard I read somewhere that the DAB transmissions would be "turned up" at switchover, and I really hope they are, as I can imagine that driving around with a DAB car radio will be a totally s
t experience.
No switch off!
http://www.communityradiotoolkit.net/community_sub...
Except
"He advised MP’s present that the 2015 switchover date will only proceed if certain criteria are met and the listeners are clearly behind the policy."
I think I also read somewhere that they are waiting for a tipping point where DAB radios outsell analogue radios.
Dr Doofenshmirtz said:
We should be using satellite radio by now. It's crazy we're still fanning around with ground based transmitters, when the obvious place for a transmitter is above our heads!
Granted the signal can't penetrate buildings (neither can DAB very well), but it's a small price to pay for a better signal when out and about.
'I may live in a cardboard box, but at least I get a good signal!'Granted the signal can't penetrate buildings (neither can DAB very well), but it's a small price to pay for a better signal when out and about.
IIRC at launch DAB radios used 22 times the power of a 'traditional' radio. That's progress for you. I believe this has come significantly down since then, but they're still not as efficient.
Simpo Two said:
Because of the much higher frequency, digital transmitters have less range (think mobile phone masts)
I have analogue radios and am jolly well sticking to them.
It's not so much that the higher frequency gives it less range, but that the higher frequency makes it more susceptible to shadowing by terrain and buildings. The current DAB system also doesn't have much in the way of error correction so where reception isn't as good, the decoding breaks down quite soon. DAB+ will likely improve reception, and the quality of the stream by using a different codec.I have analogue radios and am jolly well sticking to them.
I think that DAB is a bit of a dead end though, and will end up the way VHF and 405 line TV did. The future is DRM - Digital Radio Mondiale, and DRM+. It can use existing transmitters and infrastructure, so it doesn't need a whole new broadcast system to work. It can be used on HF frequencies giving global coverage the way AM shortwave broadcasters do now, and is very bandwidth efficient so it works nicely alongside existing analogue transmissions. DRM+ allows higher bit rates at higher frequencies, so it's possible to get extremely good quality reception.
Edited by tank slapper on Tuesday 31st January 15:47
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