One of the questions we often field as Car Tech reviewers is, "How do I get music and calls from my smartphone to play through my car's stereo without installing an aftermarket receiver?" That's a tricky one to answer, as every car's stereo is different. However, there's one thing that nearly every car audio system includes: an FM radio. This makes FM transmission the most universal way to connect a smartphone to a car stereo.
We're not the biggest fans of FM transmission technology--there are inherent limitations to its range, quality, and consistency. However, for many people, this low-tech solution is the only acceptable way.
The Gogroove FlexSmart X2 takes the FM transmitter and pairs it with Bluetooth connectivity for calls and audio streaming, giving the low-tech approach a high-tech makeover.
Controls and connections
Users interact with the X2 through a control knob and five buttons on the unit's face. The knob can be rotated to select an FM frequency and adjust volume. The control knob is pressed like a button to switch between the two modes. Surrounding the knob is a trio of buttons for toggling playback and pause of audio, skipping forward, and skipping backward. To the right of these controls is a monochromatic LED display that displays either the current FM transmission frequency or the selected volume level. To the right of the display is a pair of buttons for accepting and ending incoming calls. Farther to the right are two pinhole openings for the microphones used during calls. The X2's documentation makes no mention of noise cancellation technology being used by its microphones.
Rotate the X2 to reveal a single powered 5-volt USB port on the unit's edge that outputs 600mA of current. That's enough juice to charge most smartphones, including the iPhone and larger-screened Android phones. It probably won't fully juice your handset on your trip to the grocer's, but having access to a powered USB port does help combat the big Bluetooth battery drain. The X2 unit even ships with a pair of short USB cables (one Mini- and one Micro-) that you can keep in your car.
Over on the opposite edge of the X2 unit is a pair of 3.5mm analog audio connections. One is a line-level output that enables you to send audio from the X2 to a vehicle's auxiliary input. The other is a line input for physically connecting a device to the X2. Gogroove includes one audio patch cable for use with either port.
The X2 sits atop an 8-inch flexible stalk--putting the "flex" in the FlexSmart moniker--that can be easily bent and holds most positions. At the base of the stalk is a 12-volt connection with a built-in fuse for surge protection and a small power button. The power button itself had us a bit concerned when, on our second day of testing, it got stuck in the on position. With a bit of wiggling, we were able to fix its operation, but for the rest of the testing we elected to simply unplug the unit when we were not using it.
X2 wireless technology
The Gogroove FlexSmart X2 marries two wireless technologies: the high-tech Bluetooth and the pretty low-tech FM transmission.
Via Bluetooth, you can wirelessly pair the X2 with supported feature phones, smartphones, or portable media players with a four-digit PIN. (Yes, it's 0000.) When we attempted to pair the X2 with our HTC ThunderBolt 4G by Verizon, the handset was able to automatically complete the pairing process without the formality of the inputted PIN. Supported Bluetooth profiles include the Hands-Free Profile (HFP) for voice calls, the Advanced Audio Distribution Profile (A2DP) for streaming of audio and music, and Audio/Video Remote Control Profile (AVRCP) for basic audio playback controls.
The second piece of the X2's puzzle is an FM transmitter that outputs audio on the FM radio band, which can then be received by any FM radio that is within a short range and tuned to the proper station. Unlike most FM transmitters and radios that we've seen, the X2 can be set to transmit on both even- and odd-numbered stations, which potentially gives access to more open frequencies. These frequencies can be manually selected by rotating the control knob or an autotune feature can be used to automatically search for the cleanest open channel for audio transmission.