TechGearLab

The defining feature of the Nulaxy KM18 is its large LCD screen that keeps the user appraised of the volume level, the radio frequency being transmitted, the name of the connected device, and even the voltage of the port that it's plugged into &mdash; this last feature is an indicator of the car's battery health. The screen is mounted on a flexible neck that makes positioning it a cinch. Additionally, the unit has a volume knob and track navigation, and radio channel +/- buttons. Rounding out the suite of features is an AUX port &#40;which allows a direct connection to the headphone port of your device&#41;, a 5V/2.1A USB port, and a micro SD input for reading MP3 files directly. 
While the KM18 is packed with features, they come at the cost of size. That is not to say that this transmitter is overly big, but it's not what we'd call low profile either. Moreover, the large display screen is a bit heavy for its spindly neck and can result in the unit moving away from the user as she pushes, for example, the phone call receive button. However, the length of the neck may be a boon for those with electric sockets deeply set in the car's console. If the size of this unit suits your needs, then you'll be happy to know that it delivers a very loud, high-fidelity sound.  

The defining feature of the Nulaxy KM18 is its large LCD screen that keeps the user appraised of the volume level, the radio frequency being transmitted, the name of the connected device, and even the voltage of the port that it's plugged into &mdash; this last feature is an indicator of the car's battery health. The screen is mounted on a flexible neck that makes positioning it a cinch. Additionally, the unit has a volume knob and track navigation, and radio channel +/- buttons. Rounding out the suite of features is an AUX port &#40;which allows a direct connection to the headphone port of your device&#41;, a 5V/2.1A USB port, and a micro SD input for reading MP3 files directly. 
While the KM18 is packed with features, they come at the cost of size. That is not to say that this transmitter is overly big, but it's not what we'd call low profile either. Moreover, the large display screen is a bit heavy for its spindly neck and can result in the unit moving away from the user as she pushes, for example, the phone call receive button. However, the length of the neck may be a boon for those with electric sockets deeply set in the car's console. If the size of this transmitter suits your needs, then you'll be happy to know that it delivers a very loud, high-fidelity sound.  

amazon.com

walmart

expert-review

The 3 Best FM Transmitters of 2022

The Nulaxy NX12 is a compact FM transmitter that has about the same profile as a standard USB car charger. The unit transmits loud, clean sound with strong bass that is amplified with an optional bass booster feature. Despite the compact size, the unit sports three ports &#40;a Quick Charge 3.0, Type C PD 18W, and a standard USB port for thumb drives or direct connection of a phone or MP3 player&#41;, a volume knob as well as a channel button and display. Additionally, answering incoming calls is as easy as pressing the volume knob and speaking into the unit's built-in microphone.
While we appreciate the compact size of the NX12, we did experience some frustration with the positioning of both the QC and USB-C ports. When the unit is plugged in, these ports are almost flush with the car socket, making accessing them a little challenging without unplugging the unit. Additionally, when the unit is charging a device such as a phone, it produces a slightly fuzzy sound quality. That said, this transmitter has some of the best sound quality in the class and the fuzziness is quite mild compared to some other contenders.   

The Nulaxy NX12 is a compact FM transmitter that has about the same profile as a standard USB car charger. The unit transmits loud, clean sound with strong bass that is amplified with an optional bass booster feature. Despite the compact size, the NX12 sports three ports &#40;a Quick Charge 3.0, Type C PD 18W, and a standard USB port for thumb drives or direct connection of a phone or MP3 player&#41;, a volume knob as well as a channel button and display. Additionally, answering incoming calls is as easy as pressing the volume knob and speaking into the built-in microphone.
While we appreciate the compact size of the NX12, we did experience some frustration with the positioning of both the QC and USB-C ports. When the unit is plugged in, these ports are almost flush with the car socket, making accessing them a little challenging without unplugging the unit. Additionally, when the NX12 is charging a device such as a phone, it produces a slightly fuzzy sound quality. That said, this transmitter has some of the best sound quality in the class and the fuzziness is quite mild compared to some other contenders.   

FM Transmitter Comparison