Owners of Xiaomi, Redmi and POCO smartphones often face situations where wireless headphones are not working at full capacity.SBC's standard codec, which is on by default, compresses sound too much, depriving music compositions of depth and detail.However, most modern Xiaomi models support more advanced coding standards, such as AAC, which provide significantly better sound.
The problem is often not hardware limitations, but rather the software settings of the Android operating system and the MIUI shell or HyperOS. The system can automatically select the basic codec for maximum compatibility, ignoring the capabilities of the connected headset. To fix this, the user needs to manually intervene in the operation of the Bluetooth stack through the developer menu.
In this guide, we will discuss how to force AAC to be enabled, what nuances exist for different firmware versions, and why this may not work on some devices, how to check the current codec, which headphone models are guaranteed to support this standard, and what to do if the desired result is not achieved.
Understanding Bluetooth Codecs and Their Impact on Sound
Before we get to practical action, it's important to understand the theory. A Bluetooth codec is an algorithm that compresses audio data to be transmitted wirelessly and unpacks it in headphones. The quality of the final sound depends on the bandwidth of this algorithm and the level of compression losses.
The most common standard is SBC (Sub-band Coding is a requirement for all Bluetooth devices, but only provides basic sound quality. AAC (Advanced Audio Coding uses more sophisticated psychoacoustic models, allowing sound to be transmitted with smaller compression artifacts, especially at higher frequencies. AAC Xiaomi often makes music cleaner.
There's a codec hierarchy where each next level requires support from both the smartphone and the headphones, and if one of the devices doesn't support the standard, the system automatically rolls back to the previous level, for example, if you turn on the AAC but the headphones don't understand it, the sound just doesn't go or switches to SBC.
Xiaomi owners should know that the MIUI shell sometimes aggressively manages the power consumption of the Bluetooth module, which can lead to the fact that even with support, the system will choose a less high-quality, but more economical codec to save battery life.
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AAC provides better sound quality than SBC, but requires support on both sides of the connection: a smartphone and headphones.
Checking the compatibility of headphones and smartphones
The first step before any setup should be to check hardware compatibility. It’s pointless to try to activate AAC on Xiaomi if your headphones are physically unable to decode it. Most branded models from Apple, Sony, JBL and Samsung support this standard, but budget “nonaime” headsets are often limited to SBC only.
You can find out the list of supported codecs on the smartphone itself through system logs or special applications, but the easiest way is to look at the specification of your model on the Internet. For Xiaomi, almost all models released after 2018 are relevant, since Qualcomm and MediaTek chipsets have long learned to work with AAC.
Note the Bluetooth version. For stable AAC operation, Bluetooth 4.2 or higher is desirable, and older versions may not work stable or support high bitrate data transfer at all.
- 🎧 Specification check: Find the exact name of the headphone model and study their specifications on the manufacturer’s website.
- 📱 Android Version: Make sure your Xiaomi has Android 8.0 or higher installed, as older versions may have limited codec management.
- 🔋 Device Charge: Before testing, make sure that both the phone and headphones are charged at least 50% to eliminate the impact of energy saving.
It's also worth considering that some headphone manufacturers implement codec support in different ways, for example, the device can support AAC, but only when connected to an iPhone, and Android smartphones work only through SBC. This is rare, but it's worth checking this scenario.
Activate the developer menu on Xiaomi
To access hidden Bluetooth settings, you need to activate the developer mode. In the standard Xiaomi settings menu, these options are hidden from the eyes of the average user to prevent accidental changes in critical system settings.
The activation process is the same for all Xiaomi, Redmi and POCO models, regardless of the shell version. You will need to quickly click on the build number several times.
Go to Settings and select About Phone. Find the MIUI Version (or OS Version in the new HyperOS versions) and quickly click on it 7-10 times in a row until the pop-up notice "You've become a developer" appears.
Then go back to the main settings menu, go to the Additional (or Advanced Settings) section, and find the Developer section, and that's where all the tools you need to fine-tune the system are hidden.
What to do if the menu does not open?
Configure the Bluetooth codec through the engineering menu
Once you log in to the developer menu, scroll down to the "Network" or "Bluetooth" section. We're interested in the Bluetooth Audio Codec item, which can be "System Default" or "SBC" by default.
Click on this. You'll see a list of all the codecs that your Xiaomi smartphone supports. You can search the AAC list and select it. If you don't have AAC on the list, your smartphone doesn't have hardware or software support for that standard, and you can't turn it on.
☑️ Incorporation algorithm AAC
It's important to understand the difference between choosing a codec on a menu and actually working. By choosing AAC, you tell the system to try to use that codec. If the connected headphones don't confirm AAC support when pairing, the system still uses SBC, even if the menu selects AAC.
Once you select the codec, make sure to reconnect the headphones. Sometimes the changes only take effect after you pair the devices again. Turn off the Bluetooth on your phone, turn off the headphones, then turn everything back on and pair it.
In the same developer menu, you can find the Bitrate Bluetooth setting. For AAC, the optimal value would be 320 kbit / s or 256 kbit / s if such options are available. Lower values can degrade the sound quality, negating the benefits of the codec.
| Parameter | SBC (Basic) | AAC (Target) | LDAC/aptX (Hi-Res) |
|---|---|---|---|
| Sound quality | Low/Mediocre | High. | Studio |
| Delay (Latency) | High (200+ms) | Medium (150 ms) | Low (30-80 ms) |
| Energy consumption | Minimum | Average. | High. |
| Compatibility | 100% devices | 90% of devices | 30-40% of devices |
Use of third-party applications for diagnosis
Sometimes the built-in MIUI tools aren't enough to know what codec is being used at the moment, it can show one thing, but in practice it can work differently, and you can use specialized applications from Google Play to accurately diagnose it.
One of the most popular tools is the Bluetooth Audio Codec or Bluetooth Scanner, which can read real-world connection information, and it shows not only the current codec, but also the bitrate, sampling rate, and signal strength.
Install the app, give you the necessary permissions to access Bluetooth and location, plug in your headphones and start scanning. In the list of devices, find your headphones and look at the Codecs section, which will indicate which codec is active right now.
⚠️ Note: Some applications may require root rights for full functionality. On Xiaomi, obtaining root rights (unlocking the bootloader) will lead to a loss of warranty and may disrupt the operation of banking applications and Mi Pay.
If the app shows that SBC is active despite the settings in the developer menu, try removing the headphone pairing profile in the Bluetooth settings and re-create it.
There are also equalizer apps that can programmatically improve sound, but they don't change the transmission codec itself; they only process the signal before being sent to a Bluetooth module. For the problem of "how to make AAC on Xiaomi," they are secondary, but can be useful for finalizing the sound.
Possible problems and methods of solving them
Even if you follow all the instructions, users can run into difficulties. The most common problem is that there is no AAC item in the list of available codecs. This could mean that your Xiaomi firmware is trimmed by the manufacturer for a specific region, or the Bluetooth driver does not support this standard.
The second option is that the headphones are plugged in, but the sound is interrupted or of poor quality. This could be a sign of interference in the 2.4 GHz band. Try to move away from the Wi-Fi router or microwave oven, which often interferes with Bluetooth.
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If the sound is interrupted via AAC, try the developer menu to find the item "Disable absolute volume" and turn it on. This can stabilize the connection, although it will make it impossible to adjust the volume independently on the phone and headphones.
Another common mistake is to try to enable AAC on very old Xiaomi models (like the Redmi Note 4 and older).The hardware of these devices simply isn't designed to handle complex real-time compression algorithms without lags.
If nothing works, you can try resetting your network settings, which will delete all stored Wi-Fi passwords and Bluetooth devices, but often resolves software conflicts of the communication stack.
- 🔄 Resetting settings: Go to Settings → Connection and sharing → Reset Wi-Fi, mobile networks and Bluetooth.
- 📉 Interference: Check if the air is overloaded with other devices. Try the test in another room.
- 🎧 Reconnect: Forget the device in the Bluetooth list and pair again after the phone restarts.
Impact of AAC on Autonomy and Stability
Switching to AAC inevitably leads to more workload on the processor and Bluetooth module. The AAC encoding algorithm is more complex than SBC, which means more power consumption. In practice, the difference can be 5-10% of battery life per music listening cycle.
Also, the more complex codec is sensitive to the quality of the radio channel. If you are in a place with a large crowd and a lot of working Bluetooth devices (mall, subway), the AAC connection may be less stable than SBC.
However, for most users, the benefits of sound quality outweigh the minimal losses in autonomy. Xiaomi’s current batteries easily make up for this difference, and the stability of the connection on modern chips (Bluetooth 5.0+) is at a high level.
⚠️ Attention: When in use AAC In games, the latency may be more noticeable than when using specialized game modes or codecs aptX Low Latency. SBC or use a wired headset.
Keep a high-quality watch on your smartphone temperature during long-term music listening. The intense operation of the encoding processor can cause a light heating of the upper part of the case, where the communication module is usually located.