The Nulaxy KM18 is the best Bluetooth FM transmitter in our review and one of the most affordable Bluetooth car kits available. Its call quality doesn’t compare to higher-end kits, and FM transmission doesn’t sound as good as an AUX connection, but the KM18 performed better than the other FM transmitters in our tests. It paired to our phone quickly and has an easy-to-read display that makes finding the best FM station easy. It also has an AUX port, which means you can forgo FM transmission for a direct signal to your car stereo, which is the preferred method.
The biggest issue with FM transmitters is that radio is not the best way to listen to audio. Radio signals have a high signal-to-noise ratio, and you can hear static that may worsen depending on a number of environmental factors. We tested FM transmission quality by streaming music and making hands-free calls, and the Nulaxy KM18 received the highest marks. That said, the transmission quality wasn’t great – it simply had less static and buzzing than other FM transmitters we tested. Even so, if you turn the volume up loud enough, you won’t notice the transmission noise, so it’s still a good option for streaming music.
It also has an AUX port, which provides a much better signal than the FM transmitter. You can also use the AUX port to plug in non-Bluetooth devices to transmit audio through the FM signal. For example, you can use the AUX port to connect an iPod, which doesn’t have Bluetooth, and send your music from it to your car stereo via an FM signal. This is only necessary if your stereo doesn’t have an AUX port.
The call quality wasn’t good. It’s fine if you only occasionally make short calls, but if you’re often on the phone while you’re behind the wheel, the KM18 quickly becomes irritating. It barely beat out the other FM transmitters in our review. The same buzz and background noise that plague music FM transmissions exist in phone calls, but it’s even more apparent because you can’t drown out the noise by turning up the radio.
This Bluetooth car kit is mounted on a car charger that has an adjustable arm, and it has a USB port, which allows you to charge your smartphone. It features a 1.44 display that’s easy to read and makes it easy to navigate the radio stations and other features.
As one of the most affordable Bluetooth car kits on the market, the Nulaxy KM18 is a good option for streaming music as long as you’re fine with the limitations of FM transmitters. Audio played through an FM transmitter just doesn’t sound as good as it does when played with an AUX connection. That said, you can use this Bluetooth kit with an AUX cord if your car stereo has an AUX port.