The Mpow Streambot Flex 2-In-1 is a simple and compact Bluetooth FM transmitter that lets you play music and accept calls through your car stereo. Compared to the best Bluetooth car kits, it performed poorly in our call quality and FM transmitter consistency tests. However, it does have an AUX port, which is better for streaming audio than the FM transmitter.
The Streambot Flex is primarily a Bluetooth FM transmitter. Your smartphone sends audio signals wirelessly to the device, and it converts them to an FM signal you can pick up on your car radio. Since all car stereos pick up AM and FM stations, you simply have to find an inactive radio station and set it to transmit to that frequency. The downside is that FM transmissions are notoriously inconsistent and full of static noise.
We tested this kit’s FM transmission quality and compared it to other Bluetooth FM transmitters. It didn’t perform well. The signal was plagued with static noise, and we had to turn the music up to drown it out. The signal’s consistency was suspect as well. The volume often dipped and peaked as we drove around, even though we hadn’t touched the volume controls.
The call quality didn’t fare much better. Phone calls also had buzzing from the FM transmission. In addition, playing the caller’s voice through the stereo caused echoing and distortions that only made the transmission worse. We struggled to communicate with the other person, even on short calls.
The Mpow Streambot Flex 2-In-1 also has an AUX port. This allows you to connect the device to your car stereo with an AUX cord as long as your stereo has an AUX port. You can bypass the FM transmission issues altogether with an AUX connection, which provides much better and more consistent sound quality and call quality.
On a positive note, there’s a microphone button on the side that activates your smartphone’s personal assistant such as Siri. This feature worked quite well. Siri understood everything clearly, and it was nice having her voice amplified over the speakers, especially when receiving news on traffic conditions.
As with most Bluetooth FM transmitters, the Streambot Flex is mounted to a car charger that has a USB port to charge your phone while playing music. The mount has a flexible arm, and the device pivots 360 degrees. It is easy to adjust to fit your car.
The Mpow Streambot Flex 2-In-1 is one of the best Bluetooth FM transmitters but not one of the best Bluetooth car kits overall. This is especially the case if you value call quality. However, the combination of the FM transmitter and the AUX port make it a universal Bluetooth car kit.