April 9, 2008
Broadcasters Disagree over Increase in Digital FM Power
IBOC signals as currently regulated can't cover same area digitally as their analog counterparts: Despite what the industry has told me for years, a not-very-secret bit of information has come to the fore. The FCC limits IBOC (digital AM/FM as approved in the U.S.) to 1/100th the signal strength of analog. If you have a 100,000-watt analog transmitter, you can broadcast 1,000 watts of digital signal. I have been repeatedly over three years that this provides nearly the same footprint for digital coverage as for analog. Not so. The NAB (National Association of Broadcasters) is split over a proposal to ask the FCC for a 10fold increase in digital power. Some stations are concerned that portable devices with HD Radio built in, when they finally start to appear, will be unable to receive strong enough signals. Critics of the notion, which is still being tested by major networks and NPR, are concerned that the power boost would simply cause interference with adjacent or distant stations' analog signals. Many stations may lack the setup necessarily to power the higher signal, too.May 22, 2006
Broadcasters Seeing More Tools for HD Radio
Radio World reports that the NAB2006 conference turned heads on HD Radio because of demos, tools: New products across all aspects of a station's audio stream were demonstrated at the National Association of Broadcasters show, and Radio World said that this is helping to convince radio broadcasters that HD Radio has arrived--even if home receivers have not.
The rules for use of the spectrum on which in-channel, on-band (IBOC) digital broadcasting have changed slightly, allowing 150 Kbps of bandwidth, and this report says that Harris and BE demonstrated four-audio-channel multicasts that took up just 120 Kbps of that space. (KUOW-FM in Seattle is multicasting three channels, but not at the same fidelities.)
The editor in chief notes, "I would have liked to come to NAB and found dozens of high-impact displays with radios from a half-dozen manufacturers and signs screaming about this exciting new format. After all, stations are telling listeners about it on the air. There were only a few Boston Acoustics and Radiosophy models scattered about."
April 29, 2006
KUOW Adds Fourth HD Channel
KUOW-FM in Seattle grows from three to four HD Radio channels: The station has been one of the leaders in HD Radio broadcasting, adding an HD1 (simulcast) and HD2 (alternative programming) channel in the early days. HD3 runs at just 16 Kbps with BBC Radio (mostly voice). They're now adding a fourth HD channel at 22 Kbps which will carry music programming pending approval from both the FCC (regulation) and iBiquity (technology).
KUOW uses Neural Audio pre-conditioning hardware, which optimizes an audio signal for the particular kind of compression and encoding that it will be turned into. This pretuning produces much better results than sending raw audio into broadcasting or encoding hardware. Neural said they can now encode high-quality audio with just 16 Kbps for HD Radio channels.
April 19, 2006
Dolby To Demonstrate Surround Sound for HD Radio
At the upcoming National Association of Broadcasters (NAB) convention, Dolby Labs will demonstrate surround sound for HD Radio: The standard was designed with the notion of broadcasting 5.1 sound, but it's still just a theory, and none of the early receivers will decode it. But there's a path for this higher-fidelity format on the equipment side, and there's plenty of interest by broadcasters, especially for live and special events.
March 17, 2006
5.1 Surround at KUVO-FM in Denver
The Colorado radio station is using an advanced console and HD Radio to broadcast high-quality 5.1 sound: The station started broadcasting in 5.1 within two days of the Soundtracs DS-00 console's arrival. So far, there are no decoders for 5.1 sound on the market for HD Radio--I don't believe even the high-end 7.1 Yamaha receiver decodes that but its literature is unclear--but that will change as audiophiles interested in such things as this station's jazz recordings and live broadcasts make it worthwhile.