Owners of Xiaomi, Redmi and POCO devices often wonder about the real quality of wireless sound their gadget can provide. The standard Bluetooth connection often compresses audio files to the lowest acceptable level, depriving the listener of bass depth and high-frequency detail. However, many modern models are equipped with advanced audio codecs capable of transmitting sound in a format close to Hi-Res, but this feature can be hidden or inactive by default.
Understanding which codec is used in the smartphone-earphone pair is critical for audiophiles and audio enthusiasts. If your device supports LDAC or aptX HD, and it happens in a basic SBC, you lose a significant portion of the quality you may have paid for when you buy premium headphones. In this article, we’ll look at everything from simple settings to engineering menus to reveal the full potential of your Xiaomi audio track.
Note that codec support depends not only on the MIUI or HyperOS shell, but also on the physical Bluetooth module installed in the smartphone. The Hi-Res Audio Wireless logo on the smartphone box is the only guaranteed high-resolution codec support marker without the need for root rights. Let's take a detailed look at how to check this information yourself.
Basic standards for Bluetooth audio transmission
Before getting into the technical details of the verification, you need to understand the hierarchy of compression formats. The most common and basic standard is SBC (Sub-band Coding), which is mandatory for all Bluetooth devices, so it is guaranteed to work on any Xiaomi smartphone, but provides the lowest quality data transfer with noticeable compression artifacts.
The next layer is AAC (Advanced Audio Coding), which is the standard for the Apple ecosystem and is widely used in Android. This codec provides better compression efficiency at lower bitrates than SBC, making it a great choice for streaming services. However, for high resolution, audiophiles are looking towards more advanced technologies.
Xiaomi’s flagship models often feature support for Qualcomm codecs such as aptX, aptX HD, and aptX Adaptive.These formats provide low latency (which is important for gaming) and high bitrates of up to 24 bits/96 kHz. Sony’s competing standard is LDAC, which is capable of transmitting three times as much data as standard Bluetooth, delivering sound as close as possible to the original.
⚠️ Note: Supporting a codec with a smartphone does not guarantee it will work. Your Bluetooth headphone or headset must also support the same standard».
For a visual comparison of the capabilities of different standards, consider the following table of characteristics:
| Codec | Max. bitrate. | Frequency of sampling | Bit-of-bit |
|---|---|---|---|
| SBC | 328 kbps | 48 kHz | 16 bits |
| AAC | 256 kbps | 48 kHz | 16 bits |
| aptX HD | 576 kbps | 48 kHz | 24 bits. |
| LDAC | 990 kbps | 96 kHz | 24 bits. |
Checking through the hidden MIUI engineering menu
The fastest way to learn technical information about your Xiaomi Bluetooth module is to use a hidden engineering menu that provides access to your system settings, which are usually hidden from the average user.
Open the standard Phone app and type in the combination ##6484##. The CIT menu should appear on the screen. If the code doesn't work, try the alternative ##4636###, which opens the test menu. In the test list, find the item associated with Bluetooth or Audio.
Inside the test menu, you can often see a list of supported profiles and codecs. Look for lines that contain LDAC, aptX, or LHDC abbreviations. If those items are present and active, then your smartphone hardware is ready to work with high audio quality. However, sometimes it only displays the connection status, not the full list of features.
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If ##6484## does not open the menu, your firmware version may be blocking this access.Push the code into the Themes app or search in the settings by typing CIT.
Be careful when changing the settings in the engineering menu. Don't disable unknown features associated with the radio module, as this can lead to unstable Bluetooth or Wi-Fi. Your goal here is only to read information about supported standards.
Use of debugging USB and ADB-team
The most reliable and professional method of checking is the use of the Android debugging bridge (ADB), which allows you to directly access the Bluetooth system logs and see the exact list of codecs that the smartphone module can activate.
First, activate Developer Mode. Go to Settings → About Phone and quickly click 7 times on either MIUI Version or OS Version. Then the Developer option will appear in the Additional or Advanced Settings menu. Find the USB Debugging option there and turn it on.
Connect your smartphone to your computer through USB-On a computer where the drivers are installed. ADB, Open the command prompt and enter the following command to check Bluetooth logs in real time:
adb logcat -s BluetoothConfigOnce you type in, plug in Bluetooth headphones. In the logs, you'll see lines describing the handshake process of devices. Look for lines containing Codec Capabilities. The system will give you a list of all the codecs that the smartphone offers to the headphones. If there's LDAC or aptX Adaptive on the list, then there's support at the hardware level.
☑️ Preparation for verification through ADB
An alternative way to get a list without a PC connection is to use the terminal directly on your smartphone, but this will require root rights, which is not recommended for ordinary users because of the risk of losing warranty, so the method with a computer remains the “gold standard” of diagnosis.
Analysis through Bluetooth Analyzer Applications
If you don't want to mess with the command line and cables, you can use specialized applications from Google Play. There are a number of utilities, such as Bluetooth Codec Changer or Material Bluetooth Scanner, which can read information about the current connection and supported profiles.
Install the app and start scanning. Once you have the headphones on, it will show you the active codec and often a list of alternative codecs supported by both devices. It's a convenient way to quickly check without going deep into the technical wilds. But remember that without root rights, the app can only read information, but not change the priority of the codecs.
Some apps can show bitrate in real time. If you see a value of about 328 kbit/s, most likely SBC is working. If the value jumps around 600-900 kbit/s, you're using aptX HD or LDAC. That's a good indicator that high-quality audio is indeed being transmitted.
⚠️ Note: Analyzer apps may show incorrect data on some versions of Android due to access restrictions API Use their readings as indicative, not absolute truth.
It is also important to pay attention to the permissions that the app requests. If a simple scanner requires access to contacts or a microphone without an obvious need, it is better to abandon its use in favor of more proven tools.
The Impact of Android Version and HyperOS Shell
Codec support is not just hardware, it’s software implementation. With the release of new Android versions (12, 13, 14) and Xiaomi’s transition to the HyperOS shell, coding standards are changing, too. For example, support for LC3 (Low Complexity Communication Codec) has become the standard for Bluetooth LE Audio in Android 13, which saves battery power while maintaining quality.
Owners of older Xiaomi models may face a situation where the hardware supports aptX, but the manufacturer has not added the appropriate libraries to the firmware for a specific region.
Global ROMs sometimes have a reduced codec set compared to Chinese ROMs due to licensing restrictions. If a specific codec is critical to you, check the forums on your model before buying or reflashing.
Why can’t the codec work even with support?
Watch out for security updates and patches. Sometimes Xiaomi releases hotfixes that fix Bluetooth connection stability issues when using high bitrates, which directly affects the ability to use advanced codecs.
Frequent problems and their solution
Even if all the checks showed high-quality support, users may experience interruptions or cracks.This is often due to interference of Wi-Fi signals (which operates at the same 2.4 GHz frequency) or low battery charge of the headphones. Try turning off Wi-Fi on your smartphone and check if the stability of the connection has improved.
Another common problem is resetting the codec to SBC when switching between apps. This can be caused by aggressive battery optimization in MIUI. Go to the battery settings, find your music app (like Spotify or PowerAmp), and set the No Limits mode.
If the sound becomes monophonic when you connect, check if the Absolute Volume mode is activated in the developer menu. Sometimes, turning off this feature (Stop Absolute Volume) helps restore the stereo and the correct codec.
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The stability of a high-quality connection depends not only on the codec, but also on the distance between the devices and the absence of physical obstacles between the smartphone and the headphones.
In some cases, network resets help. Go to Settings → Connection and Sharing → Reset Wi-Fi, mobile networks and Bluetooth. This will remove all saved and return network settings to factory settings, which often eliminates software conflicts.