Tronsmart Onyx Free with UV light disinfection released for $49.99

Hey, guys! Just a heads up: The linked offer is already a bit older and the price of the gadget might have changed or it might not be available anymore.

There are some audio products from Tronsmart, but none of them have such an extraordinary feature as the latest headphones. The Tronsmart Onyx Free Bluetooth headphones have UV light disinfection built into the charger. In addition, there are technical specifications that sound promising on paper. Marketing hype or interesting gadget?

Simple design in black

The in-ear headphones and their charging box are completely black, some elements of which are matt and others reflective. On the back there is a button that is used for media control. I see similarities to the Galaxy Buds and the Redmi Airdots, although the Onyx Free have their own design. In the package you will find three pairs of earpads, a USB-C charging cable and a manual.

Disinfection by UV light?

The UV disinfection in the charger stands out of course. When I first read it, I also thought: What is this all about? But Tronsmart are not the only ones on the market that offer such a function. The light is supposed to kill bacteria and viruses that could otherwise get to your ears.

To do this, they are irradiated with UV light for 60 seconds when you put them in the charger. How effective this method is, you would probably have to check in laboratory tests first. Physical dirt cannot remove the light, so regular cleaning of the headphones remains. Therefore, the question is also whether this feature could not be saved and thus maybe lower the price a little bit more.

For these, the headphones are equipped with IPX7 water resistance, which allows you to temporarily submerge them under water. Of course, this also makes them suitable for sweaty sports activities or jogging that ends in rain.

Long life promise

The headphones should be particularly clean, but how persistent are they? Overall, Tronsmart promises 35 hours of use, at 50% volume and using the SBC Bluetooth codec. This is made up of 7 hours of running time in the headphones and 28 hours in the charger. There is also a quick charge function. Within 5 minutes, the headphones should recharge for 2 hours.

If you have heard the headphones empty and the charger box is also nearing its end, you can recharge them via the USB-C charging port. You can use the charger of your smartphone or a powerbank.

Good overall technical package

The headphones contain 6 mm drivers and a Qualcomm QCC3020 chipset. Through this you can use the aptX Bluetooth Codec, which can provide a better sound. Also included is the AAC Bluetooth codec, which is important for iPhones.

Furthermore, the Tronsmart headphones can be used in stereo and mono mode. So you can use just one earpiece to hear more of the world outside, and still hear the music completely.

There are also microphones built into the headphones. To make your voice understandable during conversations, the cVc noise canceller is used. This is designed to filter out background noise picked up by the microphone and thus make your voice easier to understand.

Physical buttons for media control

Buttons are built into the handsets for media control. These are not, as is usually the case, provided with a touch field, but are physical buttons. This way they give a natural feedback and there is no need to use vibrations or the like.

The disadvantage is that you really have to press and thus put pressure on your ear. But Tronsmart advertises here with very precise Panasonic buttons, which do not exert too much pressure. You can only judge this in practice.

The different functions of the buttons are presented in this video:

Basically, you can use it for media control, activating a voice assistant or for answering calls. You can even adjust the volume directly via the headphones. To be able to use all functions, you have to be in stereo mode. If you only use one headset, some functions may not be available.


The Tronsmart Onyx Free is a very solid in-ear headphone on the data sheet. Bluetooth codecs for Apple and Android are available and the promised runtime is also very good. In addition, there is the possibility of charging via USB-C and IPX7 water resistance.

I’ m not 100% convinced about the disinfection by UV light yet, but you can just see it as an additional gimmick. What do you think about the Onyx Free and what do you think about UV light?

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I’m the go-to guy when it comes to taking gadget pictures – And I’m always on the hunt for affordable, premium-quality audio appliances from China.

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