When I was really young, all we had was a simple AM radio in the car. Then FM came around. After that, it was 8-track tapes (yes, I’m old). Then cassette tapes came around (which I personally loved), and it was great to have your own “tunes” on any time you wanted them. Of course, that was followed by CD players. I loved those too. Now we have music in the “cloud” and music that is not really stored on any particular media (like a cassette or CD). Now we have electronic data stored on our smartphones, thumb drives (or do you prefer “flash drives”), or SD cards. With the last few changes came the ability to purchase something called an FM Transmitter. We will now take a look at what this is and how to select one.

What is an FM Transmitter?

Most modern automotive radios have mini plug input ports, USB ports, or SD card slots to allow you to hook up your music device to your radio. However, older radios do not have these input ports available. So, how do you listen to the music on your portable electronic device (phone or MP3 player)? You use an FM radio transmitter.

An FM Transmitter is a device that attaches to your portable music device (like your smartphone or MP3 player). It then converts the data or signal into another signal (usually FM) and transmits it on a specific frequency that your car radio can tune in to. This allows you to listen to your music through your vehicle’s FM radio.

Some of these transmitters have a mini plug. You plug this part into the earphone jack of your personal music device (like you would your headphones). Other transmitters attach via Bluetooth. We will look at both.

Non-Bluetooth FM Transmitters

These devices tend to be the least expensive. The quality and performance of these devices are very limited. They usually run on AAA batteries. Therefore you need to remember to change the batteries relatively often.

Also, with these devices, as the batteries lose power, their ability to transmit a good FM signal can be reduced. Thus, your music becomes full of static as you try to listen to it. To reduce the likelihood of this, try a powered Bluetooth FM Transmitter.

Bluetooth FM Transmitters

A Bluetooth FM Transmitter connects to your personal music player via Bluetooth technology. Once it makes the connection, it starts to receive music data, which it then converts and broadcasts over a specified FM signal. Usually, you can choose from several channels.

Most Bluetooth FM Transmitters need a constant and reliable power supply. They are usually built with a car power outlet (cigarette lighter) adapter. They easily plug into your car’s 12-volt power outlet.

There are many types of Bluetooth FM Transmitters available on the market. They can range greatly in price, from $10 to $150 or more.

I prefer these Bluetooth FM Transmitters for several reasons. First, they are powered by your car’s power outlet, so you don’t need to keep changing the batteries. Also, the FM signal sent to your car’s radio tends to be stronger, providing a better (less static) listening experience. Finally, these devices tend to be able to attach automatically to your smartphone or Bluetooth device, so you don’t have to plug in your personal listening device. You simply get into the car, turn on the Bluetooth FM Transmitter, and you’re ready to go.


FM Transmitters are a great way to listen to your favorite music through your car’s old FM stereo that doesn’t have the proper inputs. Whether you go with Bluetooth or non-Bluetooth, it’s a true joy to choose the music you want to listen to.

Written by Gary Pradel