Avantree CK310 Bluetooth FM Transmitter Reviewed

A Bluetooth FM transmitter can be a handy piece of equipment to have if you have an older vehicle. More and more phones are now coming without headphone jacks, so having the ability to connect to your car’s audio system wirelessly is becoming increasingly important. In this review we are going to be looking at the Avantree CK310 FM transmitter and giving you our thoughts on

How Much Does the Avantree CK310 Cost?

We paid $29.99 for the CK310 FM Transmitter and at the time of writing it is still the same price. This puts it above any other transmitter we have tested and three times the cost of the cheapest one we have got our hands on, the CSYLX BT-X7. While it is not a significant difference, the higher price does need to be justified and by the end of the review you will know if it is.


Below we have listed the specifications for the CK310 as per Avantree’s website

Bluetooth Version4.1
Bluetooth Profiles HSP, HFP, A2DP, AVRCP
Frequency Range88.1 to 107.9 MHz
Transmission range 10 m (30 ft)
Battery Capacity 370mAH Lithium-ion battery
Talk Time7 hours
Music Time9 hours
Standby Time9 hours

First Impressions (Packaging, etc,)

The Avantree CK310 came in a slender box with the main features listed on the left-hand side, and some more information on the rear. If you register within 30 days Avantree gives you a 24 month warranty, but we didn’t do this so can’t give you a rundown of what is involved.

The contents of the box contains the Avantree CK310 FM transmitter, a charging cable, 3M hook and loop fastener tape and some paperwork including the instructions and warranty info.

When it comes to the outside appearance of the CK310 transmitter itself, there really isn’t too much to say. There is one micro USB port, a power button, and the touchscreen display on the top.

Unlike all the car orientated FM transmitters we have tested before, the CK310 does not plug into the cigarette lighter socket, so it is a very compact device. However, because of this you either have to run it off the inbuilt 370mAH battery or keep it charging via the micro USB socket.

As the CK310 does not slot into a lighter socket, Avantree have included some 3M backings that allow you to stick the transmitter anywhere you want to. We aren’t the greatest fans of this as it means you have to clean off the residue if you want to remove the transmitter, but it is not a major problem.

The body of the CK310 is made from a shiny black plastic material, while the area where the screen is has more of a matt finish.

Battery and Charging

As we mentioned just above, the CK310 runs off a battery or can be plugged in via a micro USB cable. This is the only FM transmitter we have tested so far that is like this and to be honest we are not the biggest fans.

In short, the battery is pretty terrible. Avantree claims that the CK310 is good for seven to nine hours of use, but it feels shorter than that (we didn’t do any exact testing, but it felt like we were constantly charging it). Even if the battery does last seven hours, it really isn’t that long if you have a longer commute each day. When the battery is low the transmitter emits an audible “battery low” prompt every five minutes to let you know it needs charging.

As we weren’t happy with the battery life, we just left the CK310 plugged in all the time. However, this results in another problem. In older cars without USB sockets you will need to have a USB lighter adapter. This means that you need two devices, when you could get away with just one if you purchased a different FM transmitter like the Nulaxy KM30 for example.

Additionally, as you need to plug the CK310 in, it will take up a USB socket that could have been used for another device. Yes, you can just unplug the CK310 for a bit as the battery does let it run by itself, but it is just another annoyance for us (may not be for you however).

Connectivity and Instructions

While there really isn’t much to setting up a Bluetooth FM transmitter, we must say that the Avantree CK310 has some of the best instructions of any transmitter we have tested. They are well laid out with all the information you need to get going. Avantree also has some instructional videos as well, which is something that many other providers of FM transmitters don’t have.

Once you have mounted the CK310 (we didn’t as we swap FM transmitters quite a bit), plug it in via the included micro USB cable. The transmitter will start charging, but you can still set it up and use it while this is going on (as we mentioned in the previous section we just left it plugged in all the time after finding out that the battery life wasn’t as good as hoped).

The next step is to press the power button on the bottom left of the transmitter to turn it on. Once you have done this press the button again for three seconds until blue and red LED lights flash alternatingly. When this happens it indicates that the CK310 is in “pairing” mode and is ready to be connected.

The CK310 does automatically enter pairing mode when first turned on, so you may not need to do the step we just listed in the previous paragraph, but we had to.

With the transmitter in pairing mode, go into the Bluetooth devices list of your phone, tablet, etc. and select “Avantree CK310”.

After you have connected the CK310 to your device via Bluetooth, the next step is to adjust the frequency. Tune your car’s radio to an unoccupied frequency from 88.1 to 107.9 Mhz (you should hear some white noise/static). Following this, adjust the frequency on the CK310 to the same as the radio by using the “+” and “-“ buttons on the touchscreen.

The CK310’s touch buttons aren’t the most responsive and we found our selves wishing we had physically buttons like on other transmitters. Still, it wasn’t a major issue as you really only need to set the frequency once. Avantree does state that the CK310 enters idle mode after 8 seconds which turns off the touch buttons, so that may have been our issue. Touching the bottom half of the screen wakes the transmitter from idle mode.

The CK310 will automatically turn itself on and off to save battery. It should reconnect when you get back in range and turn your car on. We found this to be the case, but if it doesn’t happen you can manually reconnect by clicking the phone symbol on the transmitter.

We didn’t have any issues with connectivity with the CK310 and the set-up process was as easy as can be. The only real issue was changing the frequency with the touchscreen buttons. We would have preferred physical buttons for this, but as we stated it isn’t a major problem that would turn us off the CK310.

Sound Quality

While the CK310 definitely has some drawbacks, it makes up for it with its sound quality. We feel that it has the clearest audio of all of the transmitters we have tested so far. You do sometimes get a bit of white noise, but it is really no worse than other transmitters we have tested.

The audio quality isn’t as good as a wired connection however, so if you go in thinking that you may be disappointed (this is to be expected though).

An issue we did find is that the sound level is quite a bit lower with the CK310 vs a straight wired connection, a problem that seems to occur with pretty much every FM transmitter. Avantree’s device isn’t the worst for this problem, but it isn’t the best either.

Unlike some other transmitters, the CK310 does not give you the ability to adjust the volume on the transmitter itself. This wasn’t a problem for us as we just used the controls on our car’s sound system, however, it is something to be aware of.

Playing Music

The only option to play music through the CK310 is to use an app or program on your device such as Spotify or iTunes. There is no ability to play music through a USB flash drive or a microSD card like on some other transmitters (IMDEN C57 and Nulaxy KM30 for example). This wasn’t a problem for us as we are only interested in streaming music from our devices, but it may a deal breaker for some buyers.

There is a distinct lack of controls on the CK310. You can’t change/skip the current song on the transmitter itself and you can’t go back to the previous song. All this needs to be handled on your phone or device, which is a definite downside to the CK310 for some people. You can pause and play music if you press the phone button but that is about it.

Streaming music through the CK310 is no different to other transmitters we have tested, but it is definitely the worst product we have tested if you want to control music on the transmitter itself.


Like pretty much all other FM transmitters on the market, the Avantree CK310 gives you the ability to take and receive calls through your vehicle’s sound system.

To answer a call, press the phone button once and if you want to end the call press it again. Holding the phone button for two seconds will reject a call and holding it for three seconds during a call will mute/un-mute the microphone.

The call quality is much the same as the sound quality for playing music, so we had no problems with it apart from the occasional bit of white noise.

Siri/Google Assistant

While we are not big users of Siri or Google Assistant, you can use them with the CK310 by tapping and holding the phone button for three seconds.

Charging or Lack There Of

Unlike other FM transmitters the CK310 does not have the ability to charge other devices. This is a major downside of this product and is ultimately the reason why we decided to not continue using it. In our older cars we needed a normal lighter socket charging and the CK310m, where other transmitters can both play music and charge devices in one package.


If you aren’t concerned about charging other devices or don’t mind having to charge the transmitter, the CK310 is a good product. It has the best sound quality of any transmitter we have tested, is easy to set up and has great transmission range. However, for us it wasn’t the right product. We found that the battery didn’t last long enough, so we always had to have it plugged in and the lack of charging ports on the device was really annoying.

You can read a full comparison here of some of the best Bluetooth FM transmitters.


  • Ben

    From his early days playing the original Gran Turismo and with his Hot Wheels car set, Ben has had a long interest in all things automotive. His first foray into the world of automotive journalism was way back in 2009 and since then he has only grown more interested in the industry. Ben also runs and heads up the video production side of Garage Dreams, focusing on small informative documentaries about some of the world's most legendary cars.

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