Why spend the money for HD Radio?
by Norman Philips
The concept for an in band on channel (IBOC) solution for U.S radio was thought of fifteen years ago. It's finally rolling out and being supported by many large groups as well as small stations. The NRSC formally adopted the iBiquity HD Radio format as the digital radio standard for the United States at its meeting in Las Vegas. HD Radio transmitters are now being installed as fast as the manufacturers can deliver them due to the demand. A year ago an HD transmitter could be delivered in two weeks, now it's at least two months.
The decision to install HD Radio is not inexpensive so why should stations spend the money? The costs range from 30,000 to more than 200,000 depending on power level and current vintage of transmission equipment. There are multiple ways to implement HD Radio. Low level where the digital and analog signals are combined in the transmitter. High level and split level, where the two transmitter signals are combined externally. Separate/dual input antennas, where the low powered digital signal is fed to a separate antenna input. There are significant long term savings in power bills using this method. Proper planning up front can save money in operational costs for years.
Susquehanna Radio Corp started HD rollout in late 2002 to offer the listeners a better digital audio signal that is virtually free from multipath noise. Driving tests after installing HD Radio in the multipath-laden San Francisco and Cincinnati markets were very impressive. The original iBiquity format has main channel audio on both analog and digital except the digital audio frequency range is the same as a CD (20 kHz) instead of cutting off at 15 kHz. The digital signal does not have the analog pre emphasis curve (75 ms) that can cause harshness on high frequencies. In its basic form the HD Radio picks up the digital signal and will blend to the analog if there is a problem with both of the mirrored digital signals. There is an eight second delay that now exists in both analog and digital receivers to allow the radio to analyze the signals. That delay causes issues with live remotes and helicopter traffic reports. This is no different that the issues caused by profanity delays that many stations installed last year to help keep out of trouble with the FCC.
The audio codec used in HD Radio is newer and more robust than the ones used in satellite radio. This improved codec has allowed the 96 Kilobits of digital information to be split into multiple data streams allowing new uses for the signal. You now have a choice as to how your station uses the 96 kilobits of digital information.
The NPR concept of "Tomorrow Radio" that allows multiple audio channels is now being tested in several markets with good results. A single FM station might have its current analog audio and the digital stream could carry one to four additional audio channels of lesser quality. These are potential revenue streams for stations and supplemental audio choices for the listeners. Kenwood has been heavily involved in the design and testing of the multi-channel radios for NPR. The NRSC is involved in standardization of how the radios will seek the additional formats.
5.1 surround sound was the hot topic at the recent NAB in Las Vegas as five different formats were demonstrated as viable options for use in HD Radios. This is another use for the digital stream that can use up to 16 kilobits of the information available.
Not only was multi-channel audio demonstrated but there was traffic information mapping being broadcast on a local station and displayed on a DVD type receiver. Many stations have jumped on the RDS bandwagon for artist/title info. The Program Associated Data (PAD) on HD Radio is much better than RDS. Much more information is available as part of the digital stream. This feature makes the Satellite radio look dull in comparison. It is indeed an exciting time for radio.
The delay in HD Radio technology allowed satellite radio to get a three year head start on radio and that has hurt us from the promotional side. Satellite Radio is heavily promoted by their major investors Ford, GM, Honda, Daimler/Chrysler, Hyundai and others. Radio has been getting out-advertised for four years by satellite radio. IBiquity now has a PR department to help promote HD Radio. Some stations are beginning to promote the HD Radio signal with station ID's and other spots. Station website information promoting HD Radio with links to allow purchase of receivers is a great idea. The web site is also a great place to use spot replacement to use those avails in the promotion of HD Radio for your own station. It helps keep clutter off the main channel but gets out the advantages of HD Radio. If you are in a bad multipath area you can put a comparison of HD vs. analog on the site for listeners to hear the difference HD makes. Record the same bad stretch of road in both HD and analog and allow a listener to switch between the two recordings to hear the advantage of no pops, ticks, and swish. They won't hear that advantage in a static display of HD Radio in their favorite audio store.
The buzz we all hear about is satellite radio, IPOD, digital streaming, and a myriad of other audio choices for the public. Yes the competition is there and only going to get worse. HD Radio will give terrestrial radio the means to compete with a digital stream that can reach the masses soon. I say soon because the radios are just now starting to be delivered. They are more available on Internet sites than in stores. They should start arriving as OEM in 2007 car models. If radio does not create a demand for HD Radio in the stores then who will? The audio quality and features available in HD Radio are exciting and should move terrestrial radio nicely into the digital era for years to come. We have an educational and promotional challenge ahead of us for our listeners. We need to install HD radio and promote it or terrestrial radio might become a thing of the past in ten years.
Norman Philips is VP/Director of Engineering, Susquehanna Radio Corp.
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