Modern Xiaomi smartphones, which are based on the shell MIUI or HyperOS, offer users a wide range of options for customizing multimedia experiences. However, standard audio settings often limit the potential of quality wireless headphones using basic compression algorithms. Many device owners do not even suspect that their gadget is able to transmit audio in Hi-Res format if you activate hidden functions.
Changing the type of codec is not just a technical whim, but a real way to improve detail and reduce audio latency when watching videos or games. In this article, we will detail how to access a developer's engineering menu and switch the data protocol to a more advanced one. You will learn about the differences between SBC, AAC, aptX and LDAC to make an informed choice for your pair of headphones.
Consider that the result depends on hardware support from both the smartphone and the connected headset. Xiaomi in its flagship models for several years, has been implementing advanced chips Qualcomm that support high-bitrate audio. Let's figure out how to make this bundle work at full capacity.
What is an audio codec and why should you change it?
An audio codec is an algorithm that compresses the audio signal to be transmitted over Bluetooth and unpacks it on the receiving device side. Because the wireless channel bandwidth is limited, the source file is compressed. The more perfect the algorithm, the less quality loss occurs during this operation, and the closer the sound is to the original.
The standard protocol for all devices is SBC (Sub-band Coding). It provides basic quality sufficient for phone calls or podcasts, but when playing complex music, its shortcomings become obvious. The sound can seem flat, high frequencies and bass depth are lost. Switching to a more advanced codec allows you to reveal the dynamics of the track.
But blindly switching to maximum settings doesn't always have a positive effect. If your headphones don't support the format you're looking for, your smartphone will force you to go back to SBC or AAC. So you need to make sure that the hardware is compatible before you change the settings. The key is that you have the right chip in your Bluetooth headphone, not just your phone.
Owners of Xiaomi devices often face a situation where the phone automatically selects a suboptimal codec due to software limitations or pairing errors. Manual setting through the developer menu allows you to bypass these restrictions and fix the desired coding algorithm.
⚠️ Warning: Forced installation of an unsupported codec can result in complete absence of sound or strong digital distortion (cod).If after changing the setting, the sound is gone, simply reconnect the device or reset the Bluetooth settings.
Preparing the device for changing settings
Before you start modifying system settings, you need to prepare your smartphone. First of all, make sure that your Bluetooth headphones are charged and are in close proximity to the phone. The setup process is best done in a static position to avoid connection breaks during testing.
The second important step is to update the software. Xiaomi regularly releases patches that improve the stability of the Bluetooth stack. Go to Settings → About the phone and check for MIUI updates. On older versions of the firmware, some codecs may not work stable or are not available.
It is also recommended to clear the list of previously paired devices that you do not use, which will reduce the load on the communication module and eliminate addressing conflicts. Go to Bluetooth settings, click on the gear icon next to the unwanted device and select "Forget the device."
To access advanced audio options, you'll need to activate hidden mode, which is standard Android procedure that doesn't require root rights, and the key is to follow the sequence carefully so you don't activate other experimental features that might affect the system.
☑️ Preparation of the Xiaomi smartphone
Activation of developer mode on MIUI and HyperOS
Developer Mode is a hidden partition in the system, designed to debug applications and test features. In Xiaomi shells, access to it is closed by default so that inexperienced users do not accidentally change critical settings.
Open the Settings app and scroll down to About Phone. Find the MIUI Version (or OS Version in HyperOS). You need to quickly click on that 7-10 times in a row. After a few clicks, a pop-up message will appear with a countdown of the steps before activation.
When you see a notification saying, “You’re a developer!”, you can move on to the next step, and in some models, especially in the global versions, the system may require you to enter a screen unlock password to confirm the action, a security measure that prevents accidental activation of the mode.
Once activated successfully, a new section will appear in the main settings menu, usually in the “Additional” category or immediately in the list of basic settings, called “Developers” and this is where the tools for managing Bluetooth codecs are located.
Setting up Bluetooth audio codecs
When you log in to the Developer menu, scroll down to the Network or Bluetooth section, and we're interested in the Bluetooth Audio Codec, which can be the default setting for System Default or SBC, and clicking on this section will show you a list of all the codecs your smartphone theoretically supports.
The choice of a particular codec depends on your priorities: sound quality or connection stability. For example, LDAC provides the highest bitrate, but can consume more power and be sensitive to interference. aptX Adaptive balances between quality and latency, which is ideal for gaming.
If you choose a codec, but the headphones continue to work in SBC mode, then the headset does not support the selected format, in which case the phone will automatically roll back to the basic protocol. For forced verification, you can use the Bluetooth Audio Codec app from Google Play, which shows the active codec in real time.
Also available in this menu are sampling frequency and color depth settings. For LDAC, you can choose 990 kbit / s, 909 kbit / s or 660 kbit / s. The maximum value gives better sound, but the minimum - a more stable connection in noisy ether (for example, in the subway).
| Codec | Bitrate (max) | Quality. | Delay. |
|---|---|---|---|
| SBC | 328 kbps | Basic | Tall. |
| AAC | 256 kbps | Good. | Medium |
| aptX | 352 kbps | High. | Low. |
| LDAC | 990 kbps | Hi-Res | Tall. |
⚠️ Note: When using high-resolution codecs (LDAC, aptX HD) The battery life of the smartphone may be reduced by 10-15% Due to the increased load on the processor and Bluetooth module.
Use of the Engineering Menu for Advanced Users
For those who are not afraid to experiment, the system code allows you to access the engineering menu, which allows you to see more detailed information about the status of the radio module. Type ##6484## or ##3646633## (code may vary depending on the processor).
In the EngineerMode menu that opens, you can go to the "Bluetooth" → "Bluetooth Audio" tab, where you can manually switch profiles and check the status of the connection, but beware: changing unknown parameters in this menu can lead to malfunctioning of the communication module.
One of the useful features of the engineering menu is a bandwidth test, so you can run the Audio TX Test to see how consistently the flow of data is transmitted in the selected codec, and if the test shows errors, it's better to lower the bitrate or change the codec to a more stable one.
Some users use this menu to reset the Bluetooth stack if standard methods don't help.The Bluetooth Init team restarts the module without restarting the entire phone.This can help if the phone is "stuck" on the old codec after reconnecting.
Solving Sound Problems After Changing the Codec
A common problem after a change of settings is desynchronization of sound and video or periodic interruptions, which occurs when the channel bandwidth is not enough for the selected bitrate. First of all, try to move away from the sources of interference: Wi-Fi routers, microwave ovens and other Bluetooth devices.
If the problem persists, reset your network settings. Go to Settings → Connection and Sharing → Reset Wi-Fi, mobile networks, and Bluetooth. Note that this action will delete all stored Wi-Fi passwords and lists of associated devices, but often resolves software conflicts.
Another reason could be the app cache that plays the music through. Go to Settings → Apps → All apps, find your player (Spotify, YouTube Music, Xiaomi Music) and clear the cache. This won't delete your playlists, but updates the configuration files.
In rare cases, the firmware version itself is the culprit. On Xiaomi forums, users often report bugs in specific MIUI builds where aptX is disrupted. In this situation, waiting for an update or installing an alternative player with its own audio engine helps.
The Impact of Codec on Game Performance
For mobile gamers, latency is more important than bitrate. Standard SBC has a latency of about 200 ms, making it almost impossible to play shooters or rhythm games. Codecs of the aptX Low Latency family and aptX Adaptive reduce this to 40-80 ms.
Xiaomi smartphones with Snapdragon processors often implement Game Turbo technology, which prioritizes game traffic. However, if the Bluetooth codec is chosen incorrectly, system optimization may not work. In the developer menu, you can also find the item “Disable absolute volume”, which sometimes helps to eliminate the lags of sound.
It is worth noting that even with the support of AptX. LL And on the phone, the headphones also have to support it. TWS-Headphones use a standard aptX, which gives a delay of about 120-150 That's much better. SBC, But professional eSports may not be enough.
If you use wired headphones through a USB-C adapter, the concept of a Bluetooth codec does not apply. In this case, the sound quality depends on the built-in DAC (digital-to-analog converter) in the adapter or in the smartphone itself. Xiaomi flagships usually have good built-in DACs.
⚠️ Note: When switching codecs during the game, the application may fly out or the sound may disappear for a few seconds.