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DAB 2 FM
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WHich has better audio quality?
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FM obviously has better audio quality than DAB.
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No its not.
See David Robinson's papers to OfCom for example, which show properly
conducted listening tests which compare FM with DAB at various bit-rates.
In summary, you have to have at least 192K to stand a chance of bettering
FM.
The problem some people have with FM is poor reception. Often this is down
to poor kit* in their house. Sometimes it is local reception issues, which
include weak signals, pirate stations, traffic interference. These are rare
if the FM receiving kit is of decent quality.
(* decent quality might mean spending £30-40 on a kitchen portable rather
than £10. Or spending £30 on a FM aerial and some interconnect for the
HiFi).
- Nigel
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This is a subject that tends to lead to many argument in this NG.
Perceived sound quality can be a bit of a personal thing. Some people
actually seem to be convinced that DAB sounds good and some don't want
to accept anybody saying that it does not sound good.
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In fact heavy advertising has made people think it sounds good. If you
take joe average from the street and let him decide between FM and DAB
for the same station on the same receiver I'm sure that joe would notice
the difference.
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There is also the issue of whether you are talking about speech or
music. Speech is not such a problem on DAB as music. However since we
are comparing DAB to FM, I'd say that most of the speech stations on DAB
do sound a bit distorted which would not be the case if these stations
were on FM.
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In fact speech can be a problem if you try to use 64 kbps. It sounds
very unnatural and it is tiresome.
In the Netherlands we have a nonstop news loop at 48 kbps and that
sounds like a medium wave transmitter that has a faulty modulator. But
is uses only 35 CU at PL3 so you just have to wait until the BBC finds
that it can fit in another station by using it. (and R3 at 128 is also a
matter of time it would seem).
gr, hwh
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Going back to considering music on DAB. Personally when I first tried
DAB I thought music sounded OK. Not as good as it ought to be but OK.
The trouble is that after listening for several months the faults in the
sound of DAB seemed to become more and more obvious, until now I simply
don't want to listen to it at all. I could go into a discussion about
why this is so, but I have already had discussions about that here, and
I don't want to have to keep repeating things that I have already said.
Personally I find the audio quality on FM to be much better than DAB.
OK DAB does have better dynamic range, and does not suffer from
potential background noise (except when you get a bad signal and get the
dreaded bubbling mud sound). However I think the problems of DAB audio
far outweigh the advantages.
The worst problem, as far as I'm concerned, is the use of intensity
stereo, which now has to be used on all stereo stations. Radio 3 was the
exception, but now their bit rate has been reduced they will have to use
it too. Intensity stereo provides a very poor stereo image. It does seem
to place most sounds in the correct position between Left and Right, but
it looses all the phase differences between the channels, making the
stereo image sound very flat. I personally find that effect very irritating.
There is also the issue of compression artifacts. To be honest I
personally don't seem to notice many artifacts these days. Probably
since they improved the encoders. However other people seem to find them
very irritating.
With FM there are no compression artifacts, and the stereo image sounds
like proper stereo, not some annoying imitation of stereo. OK FM can
suffer from some interference, mostly if you are in an area of marginal
reception, but personally I don't find these anywhere near as annoying
as the problems with DAB. Besides FM in marginal areas is actually
better than DAB in marginal areas, as DAB fails in a far less graceful
manner than FM.
Richard E.
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FM, any day.
It's clear in my mind, and in my ears. FM is close **enough** to : "you
get out almost exactly what you put in".
A **minute** amount of distortion,
a **slight** loss of stereo separation (not enough to make any
significant difference),
no treble over 15kHz (big deal. I never notice the relatively small
lack of a small fraction of an octave between 15 and the 19kHz limit of
my hearing)..
.. all this IN NO WAY stops me enjoying the music, or perceiving the
audio content as I imagine it to have sounded before being transmitted.
It's CLOSE ENOUGH.
The only sensible argument against FM is the added noise. But having
grown up with noisy MW, vinyl record surface noise, cassette tapes,
etc... I find it's just as easy to ignore it as it is to enjoy a real
life concert on the beach with the crashing of the surf in the
distance. The brain just 'hears through it'.. it's no big deal.
So FM is as good (enough) to the original, plus some background noise
you can easily ignore. The signal itself it fine, there's just some
added junk.
In contrast, MP2 on DAB and Satellite is just horrid without sufficient
bitrates. It's a distorted fascimile of the original signal, which just
happens to have a marvellous S/N ratio when there are quiet moments.
Whereas FM sounds spot on when it's loud enough to mask the noise, bad
MP2 actually NEVER sounds right! Wow.. what progress. I'm not impressed
with the current state of affairs.
Good on you Mr DAB sounds worse than FM, keep up the good fight. You
may go way over the top at times in your frustration with the fact that
no-one really cares, but you and I know you're right. Even if you're
wasting your time, I still applaud your finer efforts. You might be
taken more seriously though if you weren't so rude, if I may make that
constructive criticism.
All the best.
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