Wireless FM Transmitters Vs. Cassette Adapters
Of course the first question you’ll want to ask when deciding what kind of car adapter to use with your mp3 player is whether your car’s stereo is compatible. If you drive an older car or a car with a limited built-in factory system, there’s a chance that you don’t have a tape deck. And if you drive a very new car, there’s a chance that your system is CD-only. In either of these situations, you’ll obviously want to avoid the tape-based adapter, which uses an electronic tape head to transfer information from your portable player to the car stereo. In either of these cases, assuming your car, like most, has a built-in radio, you’ll want to select a wireless transmitter. There are plenty of these devices available, ranging in price from $15 to as much as $100. These devices transmit the music from your mp3 player via a radio signal on one of a set of preselected FM frequencies, and you can use your car’s radio dial to tune in to the station you’ve chosen. The biggest difference between the competing devices is the strength of signal and the number of available stations. On the low end, the transmitters offer a choice of three or four frequencies, usually in the 88.1-88.7 range, which tend to be lesser-used by major radio stations, which cuts down on interference.
However, some interference will typically still exist, which means that unless you live in a rural area, far away from any powerful sources of radio transmission, you might still have trouble finding a clear signal. The higher-end products allow you to choose from any of the FM bands; the XtremeMac AirPlay, for example, specifically designed to work with the iPod, allows you to choose from frequencies ranging from 88.1FM to 107.9FM. Though many of the allowed stations will still receive interference, this at least gives you a wider range of choices for finding the perfect clear channel. The second factor, signal strength, is based primarily on the device’s power source. The lower-end devices tend to be battery-powered, using as little as one AA battery. While this is convenient and allows for a smaller, less cumbersome device, it often means you’ll get a weak signal; portions of the audio spectrum may be left out, or the signal may come and go, resulting in a static-filled listening experience. Other devices integrate power supply, providing power adapters that plug in to a car’s cigarette lighter. This steady power source guarantees you that, if you can find you clear station, you’ll have a better time maintaining a clear listen, since you won’t be experiencing a fluctuation in your signal strength. Also, you won’t run the risk of your batteries dying.
No matter what FM transmitter you choose, however, it will be hard for it to compete with the sound quality you’ll receive from running your mp3 player through a tape deck-based adapter. The major drawback to this kind of device is that it requires wires. Typically, a cassette-tape-shaped adapter with metal transmitter heads is inserted into the tape deck, and a small cable with a 1/4″ plug (headphone size) connects to your mp3 player. If you’re looking for a wireless experience, which FM transmitters can provide, then this type of adapter is not for you. But if it’s sound quality you’re interested in, a tape-based adapter is going to provide much better performance. This is a result of the direct electronic connection between mp3 device and car stereo. While some loss of quality is inherent, tape adapters are limited in their ability to deliver accurate sound only by the quality of their connection. That said, cassette adapters rarely have perfect connections. This is a result of the difficulty of ensuring direct alignment of the tape heads between the adapter and the stereo. The best adapters, like the one produced by Monster, feature spring-mounted heads for optimal contact and a quality connector cable. It is important to keep in mind that distortion, since this occurs prior to the signal’s being processed by the stereo’s receiver, will increase as the signal source power increases. For best performance, you should turn the volume on your mp3 player to about half of its maximum output and rely on your car stereo to adjust the volume. Though you’ll find it hard to reproduce sound at the same quality of your home stereo, you’ll find that for casual listening, most tape adapters provide a pretty accurate sound transfer, and it will beat driving around with a foot-high stack of CDs.
Of course car and car stereo manufacturers are doing their best to keep up with the digital game; increasingly, car audio companies are producing stereos that more easily and efficiently connect with portable mp3 players. These stereos are in their formative stages, however, and unless you’re buying a new car, it’s hard to justify the financial commitment required to install one of these systems. If you’re looking just to take your mp3 collection on the road with you, an FM transmitter or a cassette adapter can do pretty much all you need them to. And if you’re looking for easy-to-use, wireless adaptability, particularly if you live away from major metropolitan areas prone to radio interference, an FM transmitter with a power adapter is the way to go. Otherwise, stick to cassette adapters; you won’t get perfect sound, but you also won’t have to deal with radio interference, and for $20 or less (the typical range for these devices), it’s a minor investment to bring your entire music collection with you on the go.