TRN BT20S Pro Wireless Bluetooth Adapter Review

TRN BT20S Pro review featured

Have you been disappointed with the audio quality of TWS earphones in the past? Ever wish that you could take your favourite in-ear monitors and wear them wirelessly? Well, now you can with the TRN BT20S Pro wireless Bluetooth adapter. With the BT20S Pro you can turn any existing earphone into a TWS one, regardless of the connector type (2-pin or MMCX). Let’s dig in and see how they perform.

Disclaimer: This sample was provided for the purpose of an honest review. All observations and opinions here are my own based on my experience with the product.


  • Interchangeable/replaceable connectors
  • apt-X support
  • Great battery life
  • Stable, consistent Bluetooth connectivity

  • No onboard volume controls

TRN BT20S Pro Bluetooth modules

Design & Functionality

So, if you’re not familiar with this type of device, you might be wondering how the heck to use them. Well, you basically disconnect the cable from your earphones and then plug in the BTS20 Pro. Yes, it’s really that simple. Just make sure you order the version with the correct connection for your specific earphones!

Once you have your earphones connected to the BT20S Pro, they effectively work just like any TWS or wireless earbuds. When you take them out of the charging case they turn on automatically and enter pairing mode. If you have previously paired with your phone or source, the BT20S Pro will connect automatically as soon as you remove them from the case.

When you’re done listening or need to charge the battery, you just pop them back into the charging case. The case is fairly large but can still fit into a jeans pocket. Now, this might seem like a deterrent at first but it’s good really because it means that the case can fit your earphones as well as the BT2oS Pro modules and you don’t need to reconnect your IEMs every time you use them.

The case is semi-rigid so it offers some degree of protection for your earphones and the Bluetooth modules. On the front of the case is the USB Type-C port for charging, however, you’ll need to open the case to see the single battery status LED.

TRN BT20S Pro with CTZ6

Real World Performance and Sound

Let’s start with the battery life. According to the specs, the TRN BT20S Pro provides up to 72 hours of music playback time: 9 hours from the modules which can then be fully recharged up to 7 times! That is truly impressive. It’s better than the majority of current TWS and at the same time, you get to listen to higher quality earphones (assuming you already own some).

The Bluetooth 5.0 is enabled by the Qualcomm QCC3020 chipset which supports apt-X/AAC/SBC Bluetooth codecs. Pairing is simple and fast. While I am restricted to AAC on my iPhone, I was able to test aptX with my FiiO M6 which to my ears sounded similar in terms of audio quality but there is a noticeable improvement in latency when using aptX.

TRN BT20S Pro with charging case and Thieaudio Legacy 3 CIEM

So for testing, I hooked up the TRN BT20S Pro with some of my 2-pin in-ear monitors, namely the CTZ6, Thieaudio Legacy 3 CIEM and Mangird Tea. I can say with confidence that all 3 options proved better sounding than any TWS earphones in my collection, although the Master & Dynamic MW07 Plus comes fairly close in some cases.

Each IEM I tested had more than enough volume and the Bluetooth audio quality is excellent. There is sometimes a hint of background noise if you’re using very sensitive IEMs but it’s minimal and can’t be heard while music is playing.

I found the modules to fit securely on my ears too, even while running. The TRN marketing materials state that the BT20S Pro is water-resistant but there’s no indication of what IPX rating they have. Nonetheless, I’ve done plenty of sweating using them and so far they’ve worked perfectly (touch wood).

BT20S Pro with Thieaudio L3 custom iem


So, that’s the TRN BT20S Pro and I definitely recommend it if you want to turn your existing or future earphones into wireless models. It’s so easy, the battery life is outstanding and the audio quality is genuinely good. If you’ve been looking for a way to get the freedom of wireless but still have great sound, grab yourself a set of these.

Get the TRN BT20S here:

  • Standby time (Bluetooth modules+ charging case):180H+720H
  • Playback time (Bluetooth modules + charging case):9H+64H
  • Transmission range:10m
  • Bluetooth version:5.0
  • Charging current :DC5V,1A
  • Charging time (modules/charging case):1.5H/ 2.5-3H
  • Modular power capacity: 80mAh
  • Charging case power capacity: 700mAh
Founder of Prime Audio
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3 years ago

If yes, can I turn noise canceling ON and OFF on the divice(s)? As opposed to having to use my cellphone to do so?

Antonio Teixeira
Antonio Teixeira
3 years ago

Perhaps you where lucky

3 years ago

Great article!!!

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