Modern Xiaomi and Redmi smartphones have impressive multimedia capabilities, but sometimes standard functionality seems insufficient. The situation when you need to share an audio stream between two listeners, you often find yourself traveling, walking or just watching a movie together. Unfortunately, the built-in 3.5 mm connector or one Bluetooth module does not always allow you to solve this problem with standard methods.
Many users mistakenly believe that dual connectivity is impossible without buying additional hardware. However, the Android ecosystem and the MIUI shell (HyperOS) offer several workarounds and hidden features. In this article, we will examine the technical details of Bluetooth protocols, hardware solutions and software hacks that will help you broadcast sound to two devices at once.
It’s worth noting that success depends on the operating system version and model of your smartphone. Some low-end devices may not support advanced audio encoding features such as AptX Adaptive or LDAC, which affects the stability of the connection when duplicating the flow. We will look at all the current methods, from simple adapters to complex developer settings.
Hardware solutions: adapters and splitters
The most reliable and versatile way that works on 100% of devices regardless of the Android version is to use a physical splitter. If your Xiaomi smartphone has a 3.5mm connector, you'll need a simple audio splitter. This is a cable that has a 3.5mm Jack plug on one side and two or more headphone jacks on the other.
For today's analogue-free models, the situation is more complicated. You'll need a 3.5mm USB Type-C adapter that also needs to support forkling. It's important to understand that not all cheap adapters have a built-in DAC (digital-to-analog converter) of sufficient power to work with two pairs of headphones. With these adapters, the load on the audio chip increases, which can lead to a quiet sound or a background.
⚠️ Note: When connecting a splitter through USB-C make sure that the adapter has its own power supply or supports fast charging protocols, otherwise the smartphone may not recognize the external headset due to a lack of current.
The sound quality of this connection remains high because the signal is transmitted directly, without compression and delays typical of wireless technology, ideal for wired models with high resistance.
- 🎧 Ease of use: the principle "inserted and works" without unnecessary settings.
- 🔌 No Delays: Critical when watching a video or playing a game.
- 🔋 Independence from charge: headphones do not consume the battery of the smartphone via Bluetooth.
- 💰 Availability: the cost of a quality splitter is minimal.
Native Dual Audio feature in Android and MIUI
Starting with Android 10, the system has native support for Dual Audio, which allows you to broadcast audio to two Bluetooth devices at the same time. In Xiaomi smartphones, this feature is often built into the shell, but can be hidden or work unstable depending on the regional firmware (Global, CN, EEA).
To activate the mode, you need to connect the first pair of headphones in the standard way. Then put the second pair in pairing mode and select it from the list of available devices. If the system supports multithreading, the sound will automatically go to both devices. In some cases, you need to activate the option manually through the media menu.
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If the sound is only going to one device, try to start playing music after the second pair is connected, rather than before it, sometimes the system captures the audio stream with the first device.
The technology allows you to use different types of devices at the same time: for example, some headphones can be a TWS, and others – a full-size Bluetooth headset. However, it is worth considering that with dual connection, the audio codec can be automatically downgraded to SBC for stability of data transfer.
| Parameter | Single connection | Dual Audio (Dual Audio) |
|---|---|---|
| Codec | LDAC / AptX HD | SBC/AAC (usually) |
| Delay. | Minimum | Possible desynchronization |
| Battery consumption | Standard. | Increased by 30-40% |
| Loudness | Maximum | Could be limited. |
Use of mono-audio mode
There is a common misconception that mono-audio mode is only for people with hearing impairments. In fact, on some versions of MIUI, activating this feature can help "throw" sound to a second device if the standard method does not work, although more often it is used to bring the stereo into one channel for a single listener.
To access this setting, go to Settings → Special Features → Hearing. This is the Mono-audio switch. Turning on this option combines left and right channels. This won't create two independent streams for two different Bluetooth devices, but it will help you adjust the audio output correctly if you use specific adapters or older headphone models that don't work properly with stereo streaming.
Why is stereo important?
If your goal is to spread the sound to two different pairs, this method should be considered only as an auxiliary or diagnostic method.
Third-party applications for sound distribution
When Xiaomi’s system limitations prevent it from happening, apps from the Google Play Store come to the rescue, like Sound Assistant (from Samsung, running many Androids) or specialized Audio Share utilities try to intercept audio stream control.
The principle of their work is to create a virtual mixer, which requests advanced permissions to access the system and tries to force data to all active Bluetooth addresses. However, the effectiveness of such programs varies greatly. On new versions of Android (12, 13, 14), Google's security policy restricts application access to low-level audio drivers.
⚠️ Note: Install applications from unknown sources or modified APK-files to unlock audio functions can lead to malware infection of the device. Use only proven programs from the official store.
Some users note that helper apps can cause increased battery consumption and processor heat, as stream coding is software-based rather than hardware-based.
- 📱 Sound Assistant: allows you to fine-tune the volume for each application.
- 🔊 AmpMe: A popular music sync solution, but requires you to install the app on all devices.
- ⚙️ AudioRelay: More suitable for PC audio transmission, but has routing features.
Developer settings and hidden parameters
For advanced users who aren’t afraid to experiment, the Developer section is available, and this is where the keys to managing Bluetooth codecs and A2DP profiles lie, which directly affects the ability to connect multiple devices.
To get into this section, you need to click 7 times on the build number in the About Phone menu. Once the corresponding notification appears, go to Advanced Settings → For developers. We are interested in the Network or Bluetooth block. Here you can find the Bluetooth Audio Codec option. Switching the codec to SBC often increases stability when connecting two pairs of headphones, since this codec is less demanding on channel bandwidth.
☑️ Checking Bluetooth settings
Also worth noting is the Bluetooth MAP version, which in some cases, changing the protocol version can eliminate conflicts when pairing multiple devices, but remember that changing these settings can affect the sound quality in normal use.
adb shell settings put global bluetooth_debug_sbc_encoder_optimization 1This command, entered through ADB, can activate SBC encoder optimization, which should theoretically improve performance under double load, although support depends on the specific Qualcomm or MediaTek chipset in your Xiaomi.
Alternative: Bluetooth Transmitters with Dual Link Support
If software methods do not give a result, and you do not want to mess with wires, there is an elegant hardware solution - an external Bluetooth transmitter with Dual Link technology. This small device connects to the charging connector (via OTG) or to the audio output of the smartphone and takes on the multi-transmission function.
These gadgets have their own processor and battery. You connect the transmitter to the phone as one device, and already to the transmitter itself, two pairs of headphones. This takes the load off the smartphone module and bypasses the software limitations of MIUI. The sound quality in this case depends on the class of transmitter (see for support for aptX Low Latency).
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The external transmitter is the most stable solution for regular use, ensuring that video and sound are not out of sync.
When choosing a transmitter, pay attention to the stated support for simultaneous connection (Dual Pairing). Cheap models may require a complex pairing procedure each time you turn on.
Solution: Why isn't it working?
Even following the instructions, users can run into problems. Often the reason lies in the Bluetooth version. If your smartphone supports Bluetooth 5.0 and your headphones support 4.2, or vice versa, there can be profile conflicts. Also, distance can be a problem: when you double-connect, the radius of confident reception is reduced.
Another common scenario is a sticking-in profile of the A2DP. The system thinks the device is occupied. The solution is trivial: forget the device in the Bluetooth settings and do the pairing again, pre-switching off and on the module on the smartphone. In rare cases, resetting the network settings helps.
⚠️ Warning: Don't try to connect more than two devices at once via the standard Bluetooth module.The channel capacity will not be enough and the sound will be constantly interrupted or turned off.
If nothing helps, check system updates. Xiaomi often releases patches that fix Bluetooth stack errors in newer versions of MIUI.