Connecting TWS Earbuds to Any TV or Projector
Since my son’s arrival, watching a TV show or a movie on a TV became a near impossible task. Our little guy seemed to have a super hearing that could detect even inaudible footsteps miles away. He would wake up to the tiniest of tiny sounds. We had no choice but to put watching movies on big screen to the back burner. My poor wife resort to watching short video clips on her mobile phone with a wired earphone. I hated anything with wires and it was TWS (True Wireless Stereo) earbuds for me. We needed a way to watch a movie on the big screen without waking our baby up. None of the TVs we owned had bluetooth audio. Our projector had bluetooth, but, it was only for its magic remote. All of them, however, had USB ports and 3.5mm headphone jacks. It got me thinking that I might be able to connect TWS earbuds if I could turn these headphone jacks into bluetooth transmitters.
A Bluetooth Transmitter With a 3.5mm Plug
As it turned out, this is a common problem encountered by many people. Therefore, there were lots of products on the market. Since there were so many choices, selecting one was a daunting task. Many of these products had a bluetooth headset icon on the packaging. However, to my surprise, none of them specifically listed their compatibility with TWS earbuds. In fact, I found none that claimed to be compatible with TWS earbuds. After some research, I could broadly classify them into four categories.
- Bluetooth transmitter/receiver combo products with built in rechargeable batteries.
- Bluetooth transmitter/receiver combo products powered by USB or other power sources.
- Bluetooth transmitters with built in rechargeable batteries.
- Bluetooth transmitters powered by USB or other power sources.
Bluetooth transmitter/receiver (transceivers) combo products allow switching between transmitter and receiver function. You can use one of these modes at a time by flipping a switch. Rechargeable devices can hold charge for 3 hours to 12 hours depending on the model. These are great if you wish to spare your USBs for other purposes. For example, if you got only one USB port where you plug in USB sticks with media files. The downside is you need to keep it charged. There is also the risk of permanently damaging the device if you neglect to charge it for a long period of time. USB powered bluetooth transmitters are great if you want to plug in the device and forget about it. The only downside is you need to permanently sacrifice one USB port to power the device. In my case, I opted for a USB powered transmitter.
UGREEN CM107
After some research, I have decided to purchase Model CM107 from UGREEN. Although, UGREEN hasn’t specifically mentioned its compatibility with TWS earbuds on the product page, there were some FAQs pointing to its compatibility with TWS earbuds. CM107 had few other plus points including Bluetooth 5.0, AptX low latency technology and two simultaneous bluetooth connections. The product reviews of CM107 across several retail sites also seem to be quite decent.
Following is the technical specification of UGREEN CM107.
| Parameter | Specification |
|---|---|
| Bluetooth version | 5.0 |
| Frequency range | 2.402GHz - 2.480GHz |
| Bluetooth protocol | A2DP |
| Input | 3.5mm stereo audio or optical audio port |
| Input electrical level | 1Vrms |
| SNR | >90db |
| IOperating distance | Up to 10m |
| Input electrical level | 1 Vrms |
| Total harmonic distortion | <0.1% |
| Power supply | 5V Micro USB |
| Dimensions | L68 x W13 x H13 (mm) |
| Cable length | 50cm |
| Support two point connection | |
| Supports HiFi, SBC, AptX, and AptX LL |
AptX
AptX (Audio Processing Technology X) is an audio codec compression algorithm owned by Qualcomm. It compresses and decompresses audio as it travels from the source device to the destination device without loosing quality. This ensures high quality audio with very low latency.
Setting It All Up
Connecting and pairing CM107 is quite easy. You can get the job done by connecting the 3.5mm plug of CM107 to the 3.5mm port of your TV and powering it up with the provided micro USB cable. When you start up CM107 for the first time, it is in its pairing mode (blinking blue light). If you bring a pair of TWS earbuds within 10m, it should automatically pair up. If this fails, try switching off CM107 and manually putting it into pairing mode. A long press for 3 seconds will turn off or on the unit. Double clicking the button will put it into pairing mode. If everything fails try resetting the device. A long press of the button for 10 seconds will reset the unit to factory default. This is indicated by the blue light that keeps on for 2.5 seconds.
If you wish to pair a second bluetooth device, turn off the first device and switch the transmitter to pairing mode again. Connect the second device by bringing it closer to the transmitter (within 10m). Once it is connected, turn on the first device. The first device will automatically reconnect to the transmitter. This way, you can enjoy bluetooth audio through two devices at the same time. When pairing two devices, they need to be within 5m from each other. If you are out of the transmit range for more than 5 minutes, your earbuds will automatically disconnect. A single button press on the transmitter will reconnect the earbuds when it is back in the effective range.
In my testings’, I could sustain two stable connections with RedMi Airdots (Non AptX) and Haylou GT1 XR (AptX). However, when I connected two AptX supported earbuds (Haylou T19 and Haylou GT1 XR), the audio started to break frequently making it almost unusable. While I cannot generalize this as an AptX issue, it seemed to be the case. A single connection with any of my AptX devices worked fine. If you are planning to use this approach for watching movies, I recommend you buy a pair of TWS earbuds with at least 4 hours runtime.
