Sonnet PodFreq

Because FM transmitters let you listen to your iPod, out loud, wherever you can find an FM radio, they’ve become very popular accessories. Sonnet’s PodFreq is the latest entry into this crowded field, but whereas most vendors have tried to make their FM transmitters as small as possible, Sonnet has taken a very different approach.

The PodFreq is basically an oversized iPod case with a built-in FM transmitter. The bottom of the case provides a dock connector that passes audio and power to the transmitter when you slide in your iPod, and an LCD display lets you choose any broadcast frequency — from 88.3 to 107.7 — quickly and easily.

The PodFreq uses the line-level audio signal from the iPod’s dock connector, so the sound quality is noticeably better than transmitters that use the headphone jack. Plus you don’t have to worry about finding the “right” iPod volume setting. (The iPod’s volume level doesn’t affect the line-level signal from the dock connector, although you should disable the iPod’s EQ setting to avoid distortion.) The telescoping antenna also provides a wider broadcast range than other transmitters we’ve tested.

One drawback of the PodFreq for some users is that you cannot use another iPod case at the same time as the PodFreq. On the other hand, the PodFreq acts as a sort of case, and once your iPod is inside you get nearly full functionality. Built-in FireWire and USB ports allow you to sync and charge your iPod, and the iPod’s controls remain fully accessible. The top even flips out of the way to attach other accessories, if necessary. The only features you lose are the ability to attach an external battery pack and the use of the external line-level audio output provided by the dock base — neither of which are likely to be missed during typical PodFreq usage.

We do have a few minor complaints. For example, the PodFreq doesn’t turn off when the iPod does — you need to turn off the PodFreq manually or use its timed auto-off feature — and it doesn’t include any options for vehicle mounting. It may also be a bit pricey for some users compared to other transmitters. Finally, although the PodFreq functions as a “case,” it doesn’t protect the iPod’s face at all — even the screen is left exposed. However, even with these complaints, the PodFreq is currently our favorite FM transmitter for the iPod and gains our Playlist Pick designation.

If you want a small FM transmitter, or if you prefer to keep your iPod in your favorite case at all times, the PodFreq isn’t for you. But if you can accept the PodFreq’s form factor and price tag, you’ll be rewarded with superior sound quality, range, and ease of use.

(A version of the PodFreq is also available for the iPod mini.)–Dan Frakes