DAB-ling with radio quality
AB - Digital Audio Broadcasting - is being heavily publicised as the replacement for FM radio. Unfortunately it suffers from the problem of all digital transmission systems - broadcasters have a choice between fewer channels at higher quality, or more channels at lower quality (whereas the quality of FM is fixed). Regrettably most choose the latter, the BBC being no exception.
DAB uses compression, along the same lines as the familiar MP3 files: a bandwidth of 256kb/second (for stereo) is reckoned to give close to CD quality: 192kb/s is just acceptable: most stations use less and sound unpleasant as a result.
The BBC's flagship classical music channel, Radio 3, was transmitting at 192 kb/s until some months back (except occasionally when some of the bandwidth was stolen for sport on 'Five Live'): then the powers that be decided to reduce it to 160 kb/s, thus giving distinctly worse quality than the 50-year-old FM system. We were assured that a new encoding system meant that the quality reduction would be undetectable.
At this point I stopped listening to the unpleasant noises coming out of Radio 3, so it was only when The Guardian newspaper published a story this morning that I found out that the BBC had been inundated with complaints about the quality (which can't all have been from hi-fi buffs with expensive speakers like mine) and had been forced to reverse the decision and restore the bandwidth to 192 kb/s.
Conclusion: the people running BBC radio have cloth ears. Nothing new there, then.
Posted: Mon - October 9, 2006 at 10:29 AM by Roger Wilmut
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Published On: Mar 11, 2016 05:00 PM