The GOgroove FlexSMART X5 is an in-car Bluetooth FM transmitter that uses your car’s radio to stream music and calls. It also comes with an AUX cord, which means it works with any car stereo. The device is mounted on a car charger with an adjustable arm, but you can also clip it to your sun visor. However, in our tests, its call quality and transmission quality didn’t beat out the other top Bluetooth FM transmitter in our review.
Bluetooth FM transmitters convert the audio from your smartphone into an FM radio frequency your stereo can pick up, which allows you to take full advantage of your car’s speakers. We tested FM transmission quality by streaming music. Because radio frequencies have a high signal-to-noise ratio and can be easily disrupted, FM transmitters typically have inconsistent sound quality, no matter which one you choose. This was evident with the FlexSMART, as the there was a consistent, loud buzz, even when the music wasn’t playing.
We also tested the call quality by using the device to talk on the phone while driving through the city and on the freeway. The GOgroove FlexSMART X5 received the lowest marks in our tests. The buzz was constant throughout the calls, and the signal was distorted enough to be very irritating.
On a positive note, the FlexSMART X5 also comes with AUX-in cord, so if your stereo has an AUX port, you don’t have to use the FM transmitter. This eliminates the buzz and provides sound quality that is on par with the best AUX-in Bluetooth car kits, although it costs nearly twice as much.
The FlexSMART X5 attaches to a car charger and has an adjustable arm. The base of the charger features a USB port you can use to charge your smartphone. You can also unclip the device from the charger and attach it to your sun visor. This is the best position for making phone calls because it puts the microphone close to your mouth and minimizes the background noise it picks up. That said, if you clip it to the sun visor, you have to use the FM transmitter to make calls unless you don’t mind the AUX cord dangling in your face.
The GOgroove FlexSMART X5 is one of the best Bluetooth FM transmitters, though it was beat out by a more affordable option in our tests. The included AUX cord is the best way to connect it to your stereo if your car has an AUX port, and you shouldn’t expect high-quality audio when using it as an FM transmitter.