Techno-talk

Boat/US Magazine, July, 2002 by Chuck Husick

16

What, another radio? Would you add another radio to your boat if it could bring you 100 channels of digitally encoded audio, 60 of them music with no commercials, regardless of where in the continental U.S. you go boating? Would you pay a monthly subscription fee of $10$13 for superior audio quality, commercial free music and a clear, static and distortion-free signal, even if you boat up to about 200 miles offshore.

Two companies, XM Satellite Radio and Sirius Satellite Radio, offer these two competing services. Designed primarily to serve the mobile land market, their signals arc broadcast directly from the satellite to your receiver. While their programming is very much alike, the two systems take different approaches to delivering their signals to the user.

XM uses two very large Boeing geostationary satellites (named Rock and Roll) orbiting 23,000 miles above the Equator and positioned to provide coverage of the continent from coast to coast and beyond. Sirius uses three satellites orbiting in a figure-eight pattern at an altitude of 29,000 miles with continuous coverage assured by having two of the satellites visible at all times.

Your interest in having either of these new entertainment / information services on your boat will likely depend on the local availability of the off-the-air programming you like to hear. The wider your cruising range, the more likely you are to want one of these geographically unrestricted systems. Those who cruise long distances along and offshore from the coasts will likely consider satellite radio a must have.

Using either system is simpler than tuning in to a local AM or FM station. Blocks of channel numbers are assigned to different content: music, news, sports, comedy, talk and variety. In both services the largest content group, music, is divided into categories including classical, country, rock, R&B, urban, jazz/blues, dance, variety, Latin etc. The receiver displays the name of the artist, song title, channel name and number. Overall, the program organization is like that used for cable or satellite TV.

Sending 100 channels of high quality audio within the available signal space requires the use of very sophisticated digital encoding, broadly based on the MP3 technology used to compress audio for portable music players. The digital encoding systems used are selective, sampling music programs at a higher rate than speech to ensure the highest possible fidelity of reproduction of sound. While each satellite radio provider uses different methods of quality control for their sound, we doubt that the listener will be able to detect the difference between the two systems.

Those of us who are not on our boats often enough to justify a fixed receiver can use a plug-in receiver in a vehicle or at home when not on the boat. These receivers translate the satellite signal into a FM signal that plays through your existing FM radio and provides FM quality sound. Some also provide audio signals that can connect directly to your existing amplifier and yield CD quality or better sound. Of course, what you hear from your boat's speakers will depend only in part on the type of satellite receiver you use; the loudspeakers are the critical link in any audio system.

Regardless of the technical niceties of either system, rushing out to equip with this new gear will depend upon how appealing the programming is. The fact that much of the music is totally commercial-free may be a big selling point for some listeners.

Sirius system receiver prices range from less than $100 to about $300, for a complete kit, including the necessary antenna. XM system prices are in the $200-$300 range for a receiver / antenna kit. Some boat manufacturers are offering these satellite receivers as options on their new boats.

Chuck Husick is an engineer, pilot, sailor and the former president of Chris-Craft Boats.