DAB Radio

[Daleman]

I was thinking about this and I have a little “gadget “ with a USB connection that I can download a pod cast to and it pops in my glove box and emit’s a signal that the FM radio picks up at whatever frequency I pre select to mate them both up at, and plays the pod cast. What is to stop someone inventing a similar thing that picks up DAB and re sends it out in FM so your radio picks it up?

[Daleman]

Originally Posted by ChrisE

If you are buying an ES model this is a total c..k up. I only ever listen to the radio so upgrading the sound system is of no interest to me. Unfortunately I would need to upgrade to the high performance sound system for £400 before I can upgrade to the DAB preparation £75 (note vii on the price list) so that in future I can buy the DAB module £200.

£675 worth of extras to continue listening to the radio if they turn off R4 FM!!!!!!!!!!!!!!!!!!!!!

Since the government is so keen on switching off FM it is high time they made it illegal to sell cars with radios that will not receive its replacement. Unless of course they are trying not to mention the cost to the listener of them gaining bandwidth to sell.

At D the D prices the add on price for an ES to get reversing sensors and the audio upgrade just about pay for the SE spec. The rest (the nicer steering wheel is the only bit that I would want) is free.

Yes it makes allot of sense to go up to the SE then ,I would like to but I don’t like Neoprene Seats and upgrading to leather is not an option because I sweat like hell on my back with leather!

Volvo do not make it easy to order options for this car some of the bits obviously cost just cost a few quid to do while its being built but you are charged hundreds for it as an option .

Pure profiteering by the manufacturer.

And as far as I know you cannot order an up spec SE with down spec ES seats because potential second users expect the seats an SE comes with either as standard or as an upgrade option but not a downgrade!

[mu71rd]

yes that would work i imagine, although i suspect if the government is planning to switch off analogue frequencies for radio and TV in the future, it is so that they can use them for something else - most likely extra bandwidth for digital transmission.

that might mean that the operating frequencies of a conventional radio are blocked out by digital transmissions at the same frequency, and therefore you wouldn't t be able to tune into anything.

the thing about DAB quality is that there is nothing wrong with it in principal, just as there isn't with analogue transmission - it all comes down to how much bandwidth they allow each 'channel'. Digital TV can look great, but when they turn down the bandwidth (which is what happens on some crapper channels on sky and freeview) - then it starts looking pixellated and rubbish. same for DAB radio. I suspect some channels get a larger slice of the pie, so sound better than the more obscure channels.

unfortunately, with 'digital' - quality and quantity are directly opposed, and you know which is likely to win...

[wimorrison]

Originally Posted by Daleman

I was thinking about this and I have a little “gadget “ with a USB connection that I can download a pod cast to and it pops in my glove box and emit’s a signal that the FM radio picks up at whatever frequency I pre select to mate them both up at, and plays the pod cast. What is to stop someone inventing a similar thing that picks up DAB and re sends it out in FM so your radio picks it up?

Tangey has already posted a link for device that does what you suggest in fact there are lots of them available (check out first page of this trail)

The ssue with these devices is why recieve the broadcast in digital quality then rebroadcast on FM internally within the car - seems to defy the objective?

I have ordered a device that should plug into the USB socket using the iPod interface ( and only £25!!)- watch this space and I will tell you if it works

[Westyman]

Originally Posted by wimorrison

The issue with these devices is why recieve the broadcast in digital quality then rebroadcast on FM internally within the car - seems to defy the objective?

But FM is nearly always better quality than DAB (BBC R3 is exception) so it'll be the DAB thingy that limits quality not the FM re-broadcast.

I feel the public have been conned into DAB being better than they have at the moment. Admittedly if you receive/listen on AM e.g. BBC 5 live, then yes, DAB is better and it gives you more choice of stations, nostly those littered with annoying adverts....

Sorry, rant over....I moaned about CDs too years ago, never last...vinyl much better......must be a Luddite....

[mu71rd]

DAB is all about quantity and variety - not quality. Technically the best transmission format is AM, but they made the bandwidth small the sound quality suffered.

Trouble is, there's not enough airspace for all the digital channels, mobiles, highspeed wireless etc...

i for one would put up with a small loss of quality not to be restricted to 5 terrestrial channels again!

[wimorrison]

Originally Posted by mu71rd

DAB is all about quantity and variety - not quality. Technically the best transmission format is AM, but they made the bandwidth small the sound quality suffered.
....

???? you have me mightily confused by this statement.


AM has never been a good medium for the quality distribution of music as the bandwidth available is far too small and the manner in which the signals are radiated and received further reduce the 'quality'. FM was introduced as it had greater bandwidth enabling stereo transmission and as it is line of sight (effectively) the quality was greatly improved as the ionosphere does not affect the signal (unlike AM).

When DAB was introduced the stations were all at 192kb/s which is CD quality unlike FM which is arguably 128kb/s at best, though usually lower. The bandwidth has been reduced to allow for more stations but Radio 3 is still at 192kb/s for music. The other station vary from 128 (1,2,4) to lower for less popular stations. The commercial stations are mostly at 128 as they transit music, but some are at 64kb/s and one is at 32kb/s! Error correction (not available with analogue) provides much clearer reception.

When the analogue is retired then more bandwidth will be available for the DAB stations and quality and signal strength will significantly improve.

[mu71rd]

this is all rather hazy, but i studied FM and AM at uni. FM is band limited (30hz to 15khz) so will always sound worse than CD (20hz to 20kHz), and the way the 'stereo' signal is encoded is also slightly weird. I think the reason AM is technically superior is because it doesn't need to be band limited - but of course in practice it was never allowed enough bandwidth to be good enough, and it also suffers from all the problems you described. FM can't be compared to DAB in data rate terms because one is digital and the other is analogue.

DAB should sound better because the audio will be sampled at full bandwidth, which should sound great at a data rate of 192kb/s - but they have reduced bandwidths to allow more channels. (reason i cancelled my Setanta sports subscription years ago was because the b/width was so low i couldn't see where the ball was on the pitch!)

as far as your last statement is concerned, i wouldn't be so sure they'll increase the data rates again. I think there are huge debates going on at the moment as to what will happen to that newly available bandwidth. Everyone wants it, and i very much doubt they will give it out to radio broadcasters to increase the quality of their transmissions. More likely it will get used for new technologies (4g mobile data etc). see here

[mu71rd]

should point out there are rather large gaps in what i can remember from 10 years ago. the AM thing was definitely something i was told about, but i honestly can't remember why it was supposedly a better technology.

but it's the like the betamax v VHS battle. Betamax was always the superior format in terms of quality, but VHS won the consumer battle (largely because of adoption by the porn industry IIRC!)

-- i fear this might have gone off-topic somewhat. apologies --

[Westyman]

Great thread drift. DAB to porn!!! Brilliant!!