Sounds: What You Need to Know About Digital Radio

Even while your head is still reeling from the transition to digital television, you're being asked to consider digital radio. Digital radio, sold under the brand name HD Radio�, enables broadcasters to nest one or more digital signals within a station's standard analog signal.

The promises of digital radio resemble those of HDTV: Less noise, more choice. But so do the drawbacks: A need to buy new equipment, and confusion.

The confusion starts with the HD label itself. It's a trademark for iBiquity Digital, which licenses HD radio technology. On TV, "HD" means high-definition. On radio, it means, well, nothing. According to the Web site, "The 'HD' in HD Radio is part of iBiquity Digital's brand name for its advanced digital AM/FM system. It does not mean hybrid digital or high-definition digital."

Apparently the news did not reach manufacturer Coby, which describes its HDR 700 digital radio this way: "Enjoy crystal-clear digital broadcasts anytime, anywhere with no subscription fees in high-definition audio."

Digital radio can offer services not available on analog radio:

Multiple feeds: Like HDTV, digital radio can send several signals that deliver different programming.

A store in your car: Receivers equipped with "iTunes tagging" can remember the current song when your iPod is attached to the radio. Then you can buy the song at the iTunes store when you next synch your iPod with your computer.

An eye on the traffic: Through one nested subchannel, Clear Channel radio stations are delivering traffic updates in 50 markets.

Although the original selling point for digital radio was the promise of a clear signal, iBiquity CEO Bob Struble says the essential pitch now is "get a new radio and get lots of stuff for free."

"The audio market is very crowded," Struble concedes, and "AM/FM radio has really ceased to be a product category; it's a feature on other products. There are tens of millions of AM/FM radios sold each year, typically as part of another purchase. For us, the challenge is to get on as many devices as we can, so the consumer can sample the technology."

After four years on the market, 1,879 radio stations are broadcasting digital signals (out of 13,000 total AM/FM stations), and about 930 also are delivering at least one extra channel. Twelve car manufacturers, including Ford, Kia, and Mercedes-Benz, offer digital radio as an option. About 600,000 receivers are now in use, and one industry observer foresees "slow but inexorable expansion" for digital radio.

But not easy sailing. Blogger Glenn Fleishchman was enthusiastic about digital radio just three years ago. Now, he writes, "Four years into the serious rollout, there are still only a handful of desktop radios on the market with very little to distinguish them from other, cheaper radios."

Sales of AM/FM radios have fallen 20% over the past couple of years, and both the analog and digital versions of AM/FM radio must compete with satellite radio, iPods (annual sales more than 30 million), and millions of phones that can play MP3 music files. Further competition comes from new phones and personal navigation devices that can pick up Internet radio stations.

Both digital and analog signals fade with distance, reflect from buildings to make noisy echoes, and can be blocked by buildings and tunnels. In November, 2008 The Wall Street Journal reported that "the digital signal typically doesn't reach as far as the same station's analog signal, so in many cities, the signal comes and goes as listeners drive around town."

Although digital radios automatically switch back to analog when the signal fades, the resulting delays can be distracting if they are frequent.

Reception is frequently mentioned in comments to newspapers, as one reader wrote to the Washington Post: "The range is terrible, they don't really sound much different than analog, and the reduced range and frequent drop outs more than ruin any of the supposed dubious benefits that iBiquity claims for these receivers."

Stronger signals would boost reception, but to protect existing signals from encroachment, the power of a digital broadcast is capped at 1% of each station's analog broadcast power. The digital radio industry has asked to raise the limit to 10%, but National Public Radio has said that a universal adoption of that increase would cause "a significant increase in interference." However, NPR represents many digital broadcasters, and the network says "a managed power increase can significantly improve HD Radio coverage without sacrificing analog service."

The Federal Communications Commission is developing a ruling on the power increase, but has not announced when it will be released.

What's on the market?

As usual with electronics, the first HD receivers were pricy, and several home-theater units with HD capability still cost quite a bit more than $2,500. However, prices are falling fast. Both the Sony XDR-F1HD and the Coby Electronics HDR-650 (each $99 MSRP) can feed digital radio to a home audio system. The $90 MSRP iLuv i168 clock radio has the usual clock functions, but also includes a headphone jack.

For the car, Jensen Mobile sells six "head units," which supply input to some types of car stereos, ranging from $150 to $750.

Because HD radio electronics take a lot of current, only one portable digital radio is on the market: the Coby HDR-700, MSRP $150.

The purchase decision comes down to price, reception, and competition. Price is falling, but the reception question is difficult to judge, because it depends on the upcoming FCC decision and on your exact location. But in an era of MP3 players, cell phones, and satellite radio, it's promising that the 21st century is developing into a buyer's market for audio devices and audio formats.

Published April 27, 2009