Review: Plantronics K100 In-Car Speakerphone


Car visor-ready Bluetooth speakerphone solutions offer iPhone users an affordable way to make hands-free calls in vehicles that don’t have integrated wireless calling hardware — in fact, some of the most recent visor accessories pack features that would have been impossible to include in cars only three years ago. Today, we’re rounding up four different options from three manufacturers: BlueAnt’s S4 ($100), SuperTooth’s Buddy ($60) and SuperTooth HD ($129), and Plantronics’ K100 ($80). Besides the variations in their prices, each of these units has at least one feature that makes it stand out on paper as a worthwhile option for iPhone users; only one fell below our general recommendation level.

Review: Plantronics K100 In-Car Speakerphone

The story with K100 was somewhat different than with the other speakerphones—a tale of starts and stops. While K100 is slender and cleanly designed, it had some unusual interface and performance issues, and there’s only one major feature that distinguishes it from the others: an FM transmitter is built in so that you can hear audio through the car’s speakers rather than the one K100 has inside. And unlike the other units in this roundup, K100 makes some compromises in order to achieve its slim size and price—it’s thinner and less expensive than BlueAnt’s S4 and SuperTooth HD, but not SuperTooth Buddy. One of the compromises is in battery life: it’s rated for 17 hours of talk time and 15 days (360 hours) of standby time, both lower than all of the others reviewed today. The other is a simpler mounting system: a metal clip is permanently attached to the back rather than magnetically bonded, so removing it for recharging isn’t quite as convenient.


Review: Plantronics K100 In-Car Speakerphone

There are several positives to report on K100 relative to Buddy. First, the boxy Plantronics unit mounts in portrait rather than landscape orientation, consuming less horizontal space on a car visor than Buddy. Second, it has a conventionally oriented micro-USB port on the side for recharging, and comes with a micro-USB cable and car power adapter. And third, it works not only as a speakerphone but also as an A2DP music streaming device, effortlessly broadcasting music and audiobooks in addition to phone calls. Buddy doesn’t do that at all—neither do most of the in-car Bluetooth systems we’ve tested. Though the other rivals we review today both can do the same thing, they’re both more expensive than K100, as well.

At this point, the story with K100 becomes mixed. Start with the audio quality of the $80 unit, which was roughly on par with the $60 SuperTooth Buddy under ideal circumstances—approximately equivalent to the dual noise-canceling microphone array and bottom speaker built into the iPhone 4, only a little louder on the speaker end and better-positioned near your head thanks to the visor mounting location. The “ideal” was when K100 was outside of the range of other Bluetooth devices, and not using the FM transmitter feature; callers told us that we sounded good, and we felt the same. But for reasons unknown, when other wireless devices were within range, callers actively complained about the sound quality on their side—and we had problems on ours, as well. Words appeared to be clipping off, and conversations became distorted to the point where neither the caller nor the recipient could understand what was being said. We didn’t have issues of any sort with the other units we tested here; K100 was profoundly affected. On the other hand, you’re not likely to experience these issues in most cars.


Review: Plantronics K100 In-Car Speakerphone

K100 is also the only unit in the bunch that requires tricky timing to activate the iPhone 4’s Voice Control feature. The multipurpose power button in the center of the volume dial has various tap and hold commands that need to be learned; two taps for redial, three-second presses for transferring calls to the phone, and a two-second press for Voice Control, amongst other things. Yet Plantronics gives “mute” its own button; though we appreciate minimalism as much as anyone, this wasn’t the best use of such limited on-device controls.

The FM transmitter has some issues, too. Plantronics includes an “FM” button that is effectively an on-and-off toggle for the transmitter, which to its credit uses a gentle woman’s voice to announce which of five stations it’s broadcasting on; you just tune your radio to the station and hopefully everything sounds good. If your first station doesn’t work right, you’re supposed to non-intuitively hold down the button until it starts switching between other stations—something we had to consult the manual to figure out. Unfortunately, the choices are limited to 88.3, 88.7, 89.1, 89.5, and 89.9, which may or may not be empty of radio broadcasting in your area. During our testing, a station that sounded OK at one point would become problematic as we were driving, leading to fade-outs of streaming music and phone calls, as well as interference with the iPhone’s Voice Control feature, which would pick up noise from the radio. It’s a nice feature in concept, but the execution could have used a little work.


Review: Plantronics K100 In-Car Speakerphone

Overall, the Plantronics K100 struck us as a nice attempt to bring competent performance and FM transmission to the table, but with less ideal execution than we’d have hoped. It’s worthy of a limited recommendation on the basis of what it does, but may disappoint some users because of its compromises. For the lower price, the SuperTooth Buddy doesn’t try to do quite as much, but succeeds at everything it attempts, and offers superior battery life and easier dismounting, besides. Step up with BlueAnt S4 or SuperTooth HD and you’ll get more performance, but at higher prices. K100 is best selected, if at all, by someone who really needs the FM transmission or music streaming features and lives in an area where two of the included FM stations are empty.

Our Rating

Limited Recommendation

Company and Price

Company: Plantronics


Model: K100

Price: $80

Compatible: All iPhones

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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.