Disabling Absolute Volume Level (AAL) on Xiaomi MIUI 12: Complete Guide

If you’re using a Xiaomi smartphone with a MIUI 12 shell and you’re facing an uncontrolled volume problem when connecting to Bluetooth headphones or speakers, the fault is the Absolute Audio Level (AAL) feature, which is implemented in Android 6.0+, synchronizes volume between your phone and your wireless device, but often works incorrectly: the sound is either too quiet or jumps sharply when switching tracks. In this article, we’ll discuss how to completely disable AAL on the MIUI 12, from standard MIUI to the Xiaomi command experience.

The problem is especially relevant for owners of Redmi Note 9/10, POCO X3, Mi 10/11 and other models on MIUI 12/12.5. Bluetooth device manufacturers (such as Sony WH-1000XM4 or JBL Live 660NC) often ignore this feature, which leads to conflict with Xiaomi firmware.

What is the absolute volume level and why it should be turned off

Absolute Audio Level (AAL) is a protocol that allows an Android device to directly control the volume of Bluetooth devices (earbuds, speakers, car systems) that are connected to the phone, and in theory, it's convenient: adjust the sound on the phone and it changes automatically in the headphones.

• 🔊 Sharp volume jumps when switching tracks or applications.
• 🔇 Limiting the maximum level (sound becomes quieter than it could be).
• 🔄 Unsynchronized sliders – on the phone 100%, and headphones 50%.
• 🚫 Inability to adjust via physical buttons on the Bluetooth device.

The reason lies in the conflict between the implementation of MIUI 12 and firmware wireless gadgets. Many manufacturers (including Apple AirPods or Samsung Galaxy Buds) ignore AAL, but Xiaomi forcibly activates it for all connected devices, disabling this feature returns volume control to the user.

Method 1: Disable AAL through the Engineering Menu (without root)

The most reliable method for MIUI 12 is to use a hidden engineering menu, which does not require superuser rights and works on most Xiaomi/Redmi/POCO models. It is important to make sure that your device is not locked by the carrier before you act (for example, if you bought from the provider under a contract).

Instructions:

1. Open the Phone app and type in the combination: ##36446337## After dialing, the Engineering Mode menu will open (if the combination does not work, try ##4636## → go to Audio).
2. From the engineering menu, select Hardware Testing → Audio → Bluetooth.
3. Find the Absolute Volume option (can be called ABS Volume or AVRCP Version).
4. Change the value from Enabled to Disabled.
5. Save the settings and restart the phone.

After you reboot, plug in your Bluetooth device and check that the volume slider on your phone and headphones is independent. If you don't have Absolute Volume, move on to the next way.

Method 2: Use of the ADB-Teams (for advanced users)

If the engineering menu fails, you can turn off AAL via Android Debug Bridge (ADB), which requires you to connect your phone to your computer, but it works on all versions of MIUI 12. Importantly, after updating the firmware, the settings can be reset — you have to use them again.

Step-by-step:

1. Download and install ADB Tools on PC.
2. On your phone, activate Developer Mode: Settings → About Phone → MIUI Version (click 7 times) Then go back to Settings → Additional → For Developers and turn on USB Debugging.
3. Connect your phone to your PC through USB-cable (select File Transfer Mode).
4. Open the command line (Windows) or the terminal (macOS/Linux) in the folder with adb.exe and execute commands in order: adb devices (should appear your device) adb shell settings put global settings bluetooth_a2dp_offload_disabled 1 adb shell settings put global bluetooth_hfp_offload_disabled 1 adb shell settings put global bluetooth_avrcp_version 1.3
5. Reboot the phone.

These commands disable the hardware acceleration of sound via Bluetooth and lower the version of the AVRCP protocol (which is responsible for volume control) to 1.3. Once applied, the AAL will be deactivated, but minor delays in playback are possible.

Method 3: Editing system files (requires root)

For users with an unlocked bootloader and Magisk installed, there is a radical method - editing the system file build.prop. This is a risky way, but it gives 100% result. Changing build.prop can lead to unstable system operation or loss of warranty.

Instructions:

1. Install any file manager with root support (such as Root Explorer or Solid Explorer).
2. Go to /system/build.prop and open the file in the text editor.
3. Add a line to the end of the file: persist.bluetooth.a2dp_offload_cap=sink
4. Save the changes, set the rights 644 (rw-r-----).
5. Reboot the phone.

This line forcibly disables support for A2DP Offload, the technology that is responsible for synchronizing volume. Once rebooted, AAL will be completely deactivated, but the sound quality on some devices may decrease (due to disabling hardware decoding of aptX or LDAC codecs).

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Before editing build.prop, back it up! copy the file to SD-If you change the phone, you can restore the original version through the cloud. TWRP.

Comparison of methods: what way to choose

Each of these methods has its pros and cons, and below is a comparison table that will help you decide on the choice:

For most users, the best solution is an engineering menu or ADB. If you are not afraid of risks and want a constant effect, use build.prop, but only if you have a backup and experience with root.

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On devices with MIUI 12.5 and later, the engineering menu can be blocked, in which case ADB is the only working way without root.

Frequent Mistakes and How to Avoid Them

When you turn off AAL, you often have typical problems, and here are the most common ones and how to solve them:

• 🔄 Settings are not saved after the reboot: Reason: Some versions MIUI 12 resets the parameters of the engineering menu. ADB or edit build.prop.
• 🔊 The sound became quieter after the shutdown AAL: It's okay. AAL The volume is controlled by the Bluetooth device itself. Increase the sound directly on the headphones or speakers.
• 🚫 The microphone in the headset does not work: Disconnect AAL may affect the protocol HFP (For calls. - Return settings. AVRCP version 1.4 through ADB: adb shell settings put global bluetooth_avrcp_version 1.4
• 📱 Phone stopped seeing Bluetooth devices: Reset network settings: Settings → Connections → Bluetooth → ⚙️ → Reset the settings.

⚠️ Note: On Xiaomi devices with MIUI 12 for the European Region (EEA) The engineering menu can be blocked. ADB or install a global firmware (e.g. xiaomi.eu).

Alternative solutions: if nothing has worked

If all of the ways to disable AAL have failed, consider alternatives:

• 🎧 Use headphones in mode AAC instead SBC: Some devices (such as AirPods) are ignored. AAL when connected via codec AAC. To force it to activate, use the Developer Options app or Bluetooth Codec Changer.
• 🔄 Update the firmware of your Bluetooth device: Check the headphone manufacturer's or speaker's website for firmware updates. For example, for Sony WH-1000XM4 There are patches that correct conflicts with AAL.
• 📱 Install custom firmware: Firmware like LineageOS or Pixel Experience have no problems with the software. AAL. Minus - loss of function MIUI (For example, the Game Turbo or Second Space).
• 🔊 Use an external Bluetooth transmitter: Connect an adapter to your phone (e.g., Avantek) APTX) through USB-C. It bypasses system constraints. MIUI and transmits sound without AAL.

If you decide to reflash the phone, consider: to unlock the bootloader, Xiaomi requires a binding Mi Account and a wait of 7-30 days (depending on the model). Detailed instructions for unlocking can be found on the official website.

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Before installing custom firmware, check compatibility with your model at the [XDA Developers] forum(https://forum.xda-developers.com/).Some firmware may not support cameras or sensors.

FAQ: Answers to popular questions