Review: Kensington RDS FM Transmitter/Car Charger for iPod


FM transmitters are simultaneously amongst the iPod’s most popular and least respected accessories, for reasons we’ve explained many times: they’re virtually required to enable many car stereos to play back iPod music, but their sound quality rarely matches other, cheaper solutions. The formula is supposed to be simple: connect transmitter to iPod, pick an FM radio station to overwhelm with iPod music, press play on iPod, then tune in that station with your car radio. Pick a good transmitter and the right station, you’ll hear fairly clear audio with a small amount of somewhat annoying static, but do either thing wrong – as many people do – and you’ll hear much more static and muddier iPod music.

Review: Kensington RDS FM Transmitter/Car Charger for iPod

As the latest iteration of Kensington’s combination Digital FM Transmitter/Auto Charger – one of the first dedicated in-car transmitters to reproduce music in a way that approximated its original dynamic range – the RDS FM Transmitter/Car Charger for iPod ($90) promised to simplify and enhance its predecessor’s FM transmission experience. Both devices consist of large auto charger plugs with integrated FM transmitters and iPod connection cables; neither can be detached into its constituent parts. Employing several recent innovations, the RDS FM Transmitter does a good but not great follow-up job, falling a bit short of Belkin’s recent, more versatile, and less expensive TuneFM’s high-water mark (iLounge rating: A-) in all but one category: its novel support for RDS data broadcasting.


Review: Kensington RDS FM Transmitter/Car Charger for iPod

Available for over a decade, the Radio Data Service (RDS) lets certain FM radios receive and display text at the same time as music is playing. More popular overseas – especially in the United Kingdom – than in the United States, RDS-ready radios can display station, track and artist information, advertisements and Amber Alerts, so long as the station is broadcasting them; otherwise, the stereo’s text display will display only the station’s number on the dial. As the product’s name suggests, Kensington takes advantage of this technology in the RDS FM Transmitter, enabling the iPod to send out current artist and track details while it’s playing music.


Review: Kensington RDS FM Transmitter/Car Charger for iPod

When the feature works, it’s a cool but small trick. We were able to test the transmitter on one car stereo that properly displayed the information on its one-line text screen, and updated each time the iPod switched songs. The transmitter also worked on a second car stereo (shown below) that supported RDS as one part of a larger navigation system display. In both cases, though, the stereo was the limitation: you can see eight characters at once (“er-Jay-Z” is all you see from “Lucifer-Jay-Z” at a given moment), pretty useless by iPod standards, and have to wait for the stereo to scroll through the rest. You may also have to press your car’s RDS display button repeatedly every time you want to see the details, which is inconvenient enough in some cars to relegate this feature to the “gimmick” category instead of the “great” one. Your experience will vary dramatically from vehicle to vehicle, and many people will find that this feature adds nothing to their iPod in-car experience.


Review: Kensington RDS FM Transmitter/Car Charger for iPod

Three of our five test cars were RDS-less, leaving only the audio experience to be judged, and there our impressions were mixed. Unlike the Digital FM Transmitter, Kensington has dropped the RDS version’s ability to tune station 87.9FM – an almost always empty channel we’ve previously noted is most commonly the best for FM transmitters around the United States. Instead, the RDS Transmitter dials from 88.1 to 107.9FM in .2 increments, and saves a total of three presets in memory. You can toggle between them with a three-position rocker switch on the top of the charger bulb, and turn the unit’s power on or off with a car battery-saving switch on the bulb, both nice touches. Tuning is accomplished with a two-position (+ / -) switch on the Dock Connector plug, and uses the iPod’s screen to show you where you are on the FM dial.


Review: Kensington RDS FM Transmitter/Car Charger for iPod

Back when Kensington released the Digital FM Transmitter, it had a top-of-class FM performer – expensive, but excellent. The RDS version isn’t universally better. On a positive note, it reduces the old model’s sibilance (a sssss sound on pronounced letter S’s), but it also lowers the volume level of iPod audio a bit without commensurately lowering the level of background static from what we’d heard in the old Digital FM Transmitter. The consequence of this – and the unit’s inability to broadcast on quiet 87.9FM – was a higher static-to-music ratio on both of our test stations, 88.3FM and 103.3FM, a small step down in some ways from what the prior-generation device accomplished. Light to medium static levels were the norm during our tests – RDS sounded only a little more powerful than Kensington’s Pico, combined with the company’s new 4-in-1 Car Charger – a two-piece solution that Kensington will sell you for $85.


Review: Kensington RDS FM Transmitter/Car Charger for iPod

We’ve said this before, but it bears repeating here: $85 and $90 prices for in-car FM transmitters strike us as outrageous, and the only saving grace of the $80 Kensington Digital FM Transmitter was that it could be had for $53 with careful shopping. At the time of this review, the RDS FM Transmitter can’t be had for less than $65 from a reputable merchant, and sells in bricks and mortar stores for its full list price – as much as you’d pay today for some premium line-quality car kits, or much more complete solutions with auto mounts. For a MSRP of $50 or street price of $35, Belkin’s TuneFM delivers not only the two-piece convenience of a separate car charger and portable transmiter, but also superior overall sound quality to the RDS FM Transmitter / Car Charger. TuneFM boasts more and easier-to-access station presets, plus a collection of features – namely a cleaner monaural mode, iPod volume adjustments, and both 87.9 and international frequency tuning – that enhance your iPod’s chances of sounding better on a car or home stereo.

Our overall rating for the RDS FM Transmitter was on the edge of a B or B-, and we settled on a flat B, general recommendation only because of the overall quality of its audio output, which is good enough on the supported stations to guarantee a better than average listening experience to those willing to pay for it. Because of TuneFM, however, this isn’t a standout accessory in any other way unless you really need the RDS feature, which most people won’t, or like the on-off car battery switch, which some people will appreciate. We’d sooner have seen Kensington drop both the RDS feature and the price.

Table of Contents

Our Rating


Company and Price

Company: Kensington


Model: RDS FM Transmitter/Car Charger for iPod

Price: $90

Compatible: iPod 4G*, 5G, mini*, nano

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Jeremy Horwitz

Jeremy Horwitz was the Editor-in-Chief at iLounge. He has written over 5,000 articles and reviews for the website and is one of the most respected members of the Apple media. Horwitz has been following Apple since the release of the original iPod in 2001. He was one of the first reviewers to receive a pre-release unit of the device, and his review helped put iLounge on the map as a go-to source for Apple news.