Turn It Up: It's High-Definition Radio
Posted by Alan Stafford | Monday, January 10, 2005 5:57 PM PT
Back in the 70s, FM radio really started putting it to AM radio. FM stations had markedly better audio quality than AM did, and AM eventually got stuck with sports and talk-radio leftovers. Listen to a little bit of high-definition radio, and you might think that it will put the kibosh on AM
and FM, but I think it may end up saving them both.
IBiquity licenses HD radio to broadcasters (400 as of last count, 200 of which are actually broadcasting right now) and to auto and home radio manufacturers. The first new car to come with HD radio is supposed to be the 2006 BMW 5 series (IBiquity was quick to point out that 2006 cars will go on sale in September 2005). I listened to HD radio in a demo Beemer on the show floor, and it's pretty impressive.
The way it works is, you tune AM or FM stations just like you do now, but if the station you stop on also broadcasts in HD, it will change over to HD after a 4.5-second delay. That allows quick channel-changing?and it made it easy to tell how much better HD Radio sounds. HD channels broadcast within the FM band have up to 150Kbps (but more normally, 96 Kbps) of bandwidth to use; HD stations broadcast within the AM band have up to 36Kbps of bandwidth.
Neither of those is even close to high-definition audio standard like DVD-Audio or SACD, but they're more than competitive with satellite radio, which IBiquity says uses 48Kbps of bandwidth. The company says AM HD channels should sound as good as FM ones do now, and FM HD channels should provide CD quality sound. I couldn't tell whether that was true in the demo I got, but I could certainly tell that it sounded a whole lot better than old-fashioned AM and FM broadcasts.
IBiquity showed several sound systems, including aftermarket models for cars from Alpine, Kenwood, JVC, Panasonic, Sanyo, Delphi, and Visteon (the last two are original equipment manufacturers; those models may appear as stock equipment in new cars). Prices on these systems have come down quite a bit from last year, when the first models came out; the least expensive HD radio this year costs $399, whereas last year a comparable model cost $799. Boston Acoustics will start selling the a new version of its tabletop HD radio (its second) in April or May for $299.
National Public Radio will soon begin broadcasting four audio streams within its 150Kbps of bandwidth. You'll be able to tune into your local NPR station, which will then automatically switch to HD; HD Radios with a feature called Supplemental Audio Service (SAS) will then let you switch among the streams (with different programming on each).
why is a very partisan person by the name of juan williams allowed on npr, a public funded system
because in this country, freedom of expression is supported by our government--- or at least it used to be.
and this has *what* to do with HD Radio?