Joe's Dark Secret.

[Joe]

This forum seems to have taken on a certain confessional quality in recent days so it's time to confess my deep dark secret.

Not only do I have a DAB radio but I like it. There's no excuse; I bought it with malice aforethought so can't even say it was a present.

Seriously, I share the reservations about the way it is being introduced (and the reasons) and it's an incontrovertible fact that it is of lower quality but here's why I like it.

I bought it (by the way it's Bush 'personal' model I got cheap off e-Bay as its battery was u/s) because I wanted to listen to things that weren't being broadcast conventionally. However I quickly discovered advantages. I can go to my local shops and listen to it all the way there and back with no problem - it's now got an i-Pod battery in it - which I can't with either FM or MW. I have great difficulty getting FM in stereo but get hardly any 'bubbling mud' on digital.

As for the bit-rate issue it SOUNDS all right to me on the type of amplifiers and speakers I use. I wonder if anybody who'd walked in when I was playing it through my Little Maestro would have asked what was wrong with it as it sounded so awful.

Like with MP3 players the loss of quality is a small price to pay for the convenience.

I think it's wrong to be even thinking of switching off the analogue signal not least because it will be a tragic day when kids can't knock radios up out of razor blades, bog-roll middles and the like and the two systems should complement each other.

It has got me thinking if there were similar reservations about other broadcasting changes such as the introduction of FM and the change to 625 line TV and, now the dust has settled, if those around at the time still feel the same.

If this means I'm now persona no grata it's been nice knowing you.

Cheers
- Joe

[tiv48]

hi jo i also have two dab radios a cheap tesco portable and a full sized acustic solutions hi fi(sic) seperate mainly as you say for things not broardcast on analog ie radio7 (now radio 4 extra)but for listening to music i prefer my mono leak valve tuner.
fm radio is better quality than am
625 line uhf was better than 405 line vhf
but dab radio is worse than fm the only advantage is the amount of content
rob t

[beam me up schottky]

Was just about to say the same thing Rob ! Technology should advance not recede !

[Jamie-Skinner]

I got a cheap "Lava" DAB radio for £30.. It sounds.. well CRAP! But it doesn't matter when It's connected to my hifi. I have to say I also like them in a way, As it means I can listen to Absolute 80's without being online all the time. However I do personally notice the lower bitrate but that's probably as I always go for 320kb/s MP3 or WAVE...

[Steve_P]

Well, there are worse things you could do. I've got a hardly used one and I know for a fact that Mark has one.

The system they use could be very good actually. Like MP3, the bitrate matters. I'm sure we have all heard a dodgy MP3. The system of DAB was let down by bean counters. Like Analogue. Digital needs more bandwidth to work, and the more stations you put onto a Digital mulitplex, the less each station has, so the quality suffers. They allocate as many stations as they can get away with. Most people don't notice, some don't care and it's only people like us who notice and bother.

Before the Radio Changes of 1979, AM sounded a lot better than it does now. (There are other things that tend to make AM sound poor, but we're not discussing Optimod on here.)

To prove my point, Radio 3 always has a higher bitrate, and it sounds better for it. All that for the sound of small animals being tortured...

Cheers,

Steve P.

[Mark Hennessy]

I also have one, but it is an obvious tribute to Hacker - see the attached picture (with a couple of Hacker sets for scale). It's actually rather nice, with a snazzy touch-sensitive control surface that illuminates when you wave your hand over the top, and it sounds very good too. Especially given how small it is...

Best of all, it can be had for £45 delivered: http://www.plugonit.co.uk/product/genus-type-r - and note that this was originally an expensive radio, so what you get is far better than the "supermarket specials". Against that, also be aware that this doesn't do DAB+, but I didn't care at that price.

Apologies to any Hacker Group members who remember the long discussion this set prompted a few months back! Quite a few of these were bought as a result

I also have an Arcam Alpha DAB tuner - the first hi-fi tuner to be released in the UK - although this was free for spares or repair. One LM317T later, I was in business . It sounds very good as well, given the constraints of MP2.

My views on DAB have been expressed elsewhere, but in short we are paying the price of jumping in too soon. MP2, or more correctly MPEG1 layer 2, was pretty good in ~1990, but today many better things are available but we can't adopt them without obsoleting the existing hardware - not something the BBC wants to do.

In defence of MP2, it's actually surprisingly good at 256kb/s and more. It was optimised for live broadcast, and actually out-performs MP3 at higher bitrates. Of course, MP3 is better at lower bitrates, but MP3 is not well suited to live broadcast. I have a number of test discs for demonstrating these and other codecs, and most people are surprised at how effective these schemes are when you are genuinely comparing *just* the codec.

The last point is important because I know of lots of people who have come to the conclusion that MP3 is crappy because they are listening to a crappy MP3 player! I tell these people to put the .WAV on the same player and do a genuine comparison. Years ago I used a DAT recorder (remember them?) which sounded worse than my MiniDisc deck (remember them?). Surely MD should be worse than DAT because MD used ATRAC to compress the information, whereas DAT is completely linear? Yeah, but the DAT machine had a crappy A-D converter . Just be sure you know where to point the finger, that's all I'm saying...

All that said, there's absolutely no doubt that broadcasters have been forced to push the data rates, and also dynamic range processing (also called "compression" - generically called "Optimod", as Steve mentioned) is generally (ab)used by the majority of broadcasts. Interestingly, Classic FM don't process the DAB feed. But the CDs are normalised when ingested onto the playout system - fine for rock and pop but not such a good idea for classical. Listen for the start of the slow movement, and note how the "atmos" in the venue is much louder than in the opening movement...

Incidentally, if we went for DAB+, which uses the much more modern and shiny AAC, we would be in the same situation. More services perhaps, but still with barely adequate bit rates. Call me cynical, but you know I'm right :D

Mark

[big band heaven]

I don't have DAB - I'm not even sure if we have it here in New Zealand.

Since my original post I did just look it up on the internet and this is what I found:

New Zealand has been trialling DAB since November 2006 in Wellington and west Auckland but wants to use the new DAB+ standard once testing is finished.

Question is what is DAB+ . Is it better?

Richard.

[Yorkie]

The radio featured at that link looks excellent and keenly priced, and it recieves FM too.

I mentioned earlier that I've got a Pure Evoke 1 DAB radio, and it sounds fine to me. The only limitations are the limited number of stations that I can receive in htis location, and the irritation babbling effect when signals break up. I do wonder whether the criticisms about DAB in comparison to similar quality AM/FM are based on objective listening on similar radios, or simply a bias against DAB. UK coverage is poor - in many areas there are no DAB signals at all. My younger son lives in Matlock, which is in a valley in Derbyshire and can't receive any DAB signals not Digital TV, but should be able to later this year when TV is due to go digital. I find it very odd in this day and age that there are any areas where TV reception is poor, because all it takes is a cheap repeater station in a high spot, which even radio amateurs have been able to instal for amateur radio use for 40 years.

The bias against AM when FM was introduce was similar to the resistence to DAB. Manufacturers added FM to radios as a selling point well before many listeners could actually receive FM. The forecasted early demise of AM when FM came in with wide coverage proved to be premature. AM-only radios continued to be produced long after FM came in. It's the lack of DAB radios in cars that will slow down its introduction, by which time, who knows - DAB may turn out like Betamax, be overtaken with something else, and go down the tubes. There seems to be little enthusiasm for it in Mainland Europe.

As to MPs players, I use my i-pod nano on the occasional long journey, such as when my younger son and I go on battlefiled tours to France, Belgium and beyond by coach. I also use it when - under sufference, we visit her sister in Essex and her insufferable Daily Mail reading sports loving numpy of a husband. He's mad about sport, hard of hearing but for reasons of vanity, won't have a hearing aid. Thus, whenever we visit them, usually twice a year, he has the TV on incessantly, has all the satellite sports channels, and flips from one to another at maximum volume impervious to the wishes of antyone else who happens to be in the room. He flips from one channel to another - golf, cricket, football, snooker, back to golf, shouting at the TV screen as though his life depended upon it. I just switch on my nano, and slap on my Bose over the ear headphones and it transports me to another world - a world in which sports of any kind, are banned and forever will be. 500 tracks played at random on 'shuffle' - 25 hours listening from a gadget that is 75mm long, 6mm thick and 50m wide. Not so long ago, that would have been science fiction! To my ears, the quality of reproduction is excellent.

David

[big band heaven]

"numpy" - now there's a word i've not heard before. I like it!

[ppppenguin]

At a recent IEE lecture it was pointed out that although the bit rates on DAB are a bit on the low side they are good enough for all but critical listening. This really means fixed installations with high quality equipment. In that situation he said there is also Freeview and Freesat both of which use adequate bit rates for high quality.

Apparently there is still a lot that could be done with MP2 at current bit rates by using improved coders at the TX. Since this would be a negligible cost why isn't this being done?

Yes, we are saddled with an obsolete audio codec for DAB. It's bad that DAB receivers have only recetly been fitted with updated codec capability. Even if they have, few will dare mention it for fear of harming DAB sales. It's also a regulatory failure that car radios still don't have a mandatory "must fit DAB" on new cars.