If you’re reading this editorial, you probably already know what an FM transmitter is, and what to expect when you buy one. For the uninitiated, FM transmitters are designed to wirelessly broadcast your choice of music to any empty FM radio station—a technology that’s useful if your car stereo has no way to make a wired connection to your iPod. We’ve been very blunt about the performance of FM transmission technology in the past: our 2006 Introduction to FM Transmitters said plainly that “few iPod accessories are as abundant, or as frequently disappointing, as FM transmitters,” noting that governmental agencies such as the United States Federal Communications Commission (FCC) limit the devices’ broadcasting power.

These limits increase the amount of static interference you hear when playing music through transmitters, and generally require you to place the devices close to your car’s antenna for better sound quality. Consequently, transmitters have for years been our recommendation of last resort for iPod owners: use them only if you aren’t willing to spend the money on a wired iPod integration solution, and your car lacks a cassette tape deck with the ability to use a cheaper but better-sounding cassette adapter.


Effective now, that recommendation is becoming even stronger. During last year’s long-awaited loosening of FM transmitter restrictions in the United Kingdom, the United States saw a quiet, much less publicized shift in the opposite direction; acting to remedy numerous companies’ violations of regulations governing transmitter signal strength, the FCC began knocking on transmitter makers’ doors and demanding immediate changes. As we predicted last September, “you should expect major manufacturers to become more concerned about FCC regulations, and non-compliant transmitters (read: super-powerful ones) to become less common in products by big companies.”


This week, we’ve heard from multiple transmitter developers that these changes are in the process of being implemented, and generally without notice to consumers. Some of last year’s FM transmitters have already been changed internally to cripple their broadcasting power even further than before, without any external or packaging changes that signal the change. As a result, there’s a very good likelihood that if you’re buying an established FM transmitter, it won’t be as strong as last year’s model, and if you’re buying a brand-new device with FM transmission built-in, you shouldn’t expect it to deliver the results of your favorite prior transmitter. In short, the proximity of your car’s radio antenna to the transmitter and iPod has just become an even bigger concern.


All of this isn’t to say that all of the well-known transmitters out there have just become useless. Belkin’s popular TuneFM, Griffin’s iconic iTrip, and XtremeMac’s AirPlay series will continue to be sold, alongside dozens of transmitter-plus-car charger options from other companies, such as DLO, Kensington, and Monster Cable. Some models—the comparatively few that didn’t violate FCC restrictions to begin with—will be unchanged, and 2005-2006 vintage transmitters will continue to work at past levels until they die of natural causes. At least, on current-model iPods.


Our advice to iPod users is this: if you’ve been holding out on installing a wired iPod integration solution in your car, and frustration-free audio quality is important to you, now’s the right time to consider that upgrade. We have yet to see a competing wireless technology, such as Bluetooth, emerge as a viable mainstream car audio alternative to FM radio, and since that may not happen for months or years, your choices are either FM transmission or a wire. If you’re looking for something today, and unless you’re willing to consider positioning your new FM transmitter right next to your car’s antenna, we’d seriously recommend going with the wire, sooner rather than later.