Xiaomi’s current Redmi series of smartphones feature advanced wireless connectivity modules that allow instant synchronization of the device to any periphery. However, despite standardization of protocols, users often face nuances when they first try to pair gadgets, especially for popular models such as the Redmi 9, where the MIUI shell interface has its own unique control features.
In this article, we will take a look at the entire setup process so you can enjoy your favorite music or conversations without extra wires. You will learn not only about the standard procedure, but also about hidden codec settings that can significantly affect the quality of the audio transmitted.
Before you get to the technical steps, you need to make sure that your equipment is ready to go. Wireless connection requires that both devices are in detection mode and have sufficient battery power. Ignoring basic training rules often causes the phone simply to “do not see” the headset in the list of available devices.
Preparation of headphones and smartphone for pairing
The first step is to activate the pairing mode correctly on the headset itself. Many users mistakenly believe that simply turning on the device is enough to detect it, but this is not the case. To enter Pairing mode, you usually need to pinch the function button on the headphone or case case for 5-7 seconds until the indicator begins to flash alternating colors (most often red and blue).
On the smartphone side, you also need to perform a number of pre-checks. Make sure the Bluetooth module is activated and not in sleep mode. In some cases, the MIUI system may restrict the background scanning to save energy, so it is better to open the communication settings in advance. Also check if the phone is on "On the plane" mode, which blocks all wireless interfaces.
It's important to consider the distance between devices at the time of first connection. The optimal is to have gadgets within a meter of each other without physical obstacles. If you're trying to connect devices through a wall or from another pocket, the signal may be too weak to establish the initial handshake protocol.
⚠️ Note: If the headphones flash only one color or don’t blink at all, they may have automatically connected to another previously paired device nearby. In this case, you need to turn off Bluetooth on all other gadgets in range or reset the headset settings.
☑️ Checking before connection
Step-by-step connection instruction via MIUI settings
The MIUI interface process installed on Xiaomi Redmi 9 is intuitive, but has its own status display features. To start, open the Settings app and find the Bluetooth section. An alternative and faster way is to swipe notifications from top to bottom and click on the wireless icon, then select “Additional Settings” or just wait for the list of devices to appear.
Once the search is activated, the system will start scanning the surrounding space, and your headset should appear in the "Available Devices" list, which may match the model listed on the box, or have a standard manufacturer designation, such as AirDots, Galaxy Buds, or just Headset. Click on the device name to begin the authorization procedure.
In some cases, the system may request a pairing confirmation or input PIN-The standard code for most modern accessories is 0000 or 1234, but new models often do without this step, requiring only confirmation on the smartphone screen. After a successful connection, the status will change to “Connected”, and in the notification curtain there will be a corresponding icon with the battery level of the headphones.
- 🔍 Open “Settings” and go to the Bluetooth section.
- 📡 Click on “Search for Devices” or wait for automatic scanning.
- 🎧 Find the name of your headset in the list of available.
- ✅ Click on the name and confirm the pairing if required.
Customize sound quality and codecs in Developer Options
For advanced users who want to make the most of Redmi 9 audio, a hidden developer bar is available. This is where you can force a codec to transfer sound, which directly affects bitrate and latency. By default, the system chooses a compatible, but not always high-quality SBC codec, whereas many modern headphones support more advanced standards like AAC or aptX.
To activate this mode, go to the About Phone menu and quickly click on the MIUI build number seven times. Once the "You're a developer" notification appears, go back to the main settings menu, select "Additional" and find "Developers" option. In the list that opens, go down to the Audio section.
Here you will find the item "Bluetooth LDAC/AAC/aptX Codec." Clicking on it, you will see a list of formats supported by your phone and connected headset. Choosing a better codec can increase power consumption, but will significantly improve the detail of the sound. If the selected option does not work (sound is interrupted or missing), the system will automatically roll back to the basic protocol.
What is LDAC and should it be included?
Managing Connected Devices and Priorities
The MIUI-based Android operating system allows you to manage multiple saved profiles, but active audio playback is only possible on one device. In the Bluetooth menu, by clicking on the gear next to the name of the connected headset, you can set specific permissions, where you can prevent the device from using the microphone or playing media, leaving only the transmission of system sounds.
The Audio output feature in the notification curtain allows you to quickly switch between the phone speaker, wired headset and Bluetooth devices, which is especially convenient when you have a smartwatch and headphones connected to the phone at the same time, the system can try to display the call notification on the clock and transfer the conversation to headphones, which sometimes causes confusion.
You can use Auto Connect to manually manage priorities. If you turn this option off for a particular device, the phone won't try to connect to it automatically when you turn on Bluetooth. This is useful for gadgets that you rarely use so that they don't intercept the audio stream at the wrong time.
| Parameter | Description | Recommendation |
|---|---|---|
| Media-audio | Music and video transmission | Included for music |
| Audio input | Use of a headset microphone | Turn it off for music. |
| Contacts | Synchronization of the phone book | Turn on for calls. |
| Autoconnection | Automatic Connection when Appeared | At the discretion of the user |
Solving Common Connection Problems
Despite the stability of Xiaomi Redmi 9, users may experience a situation where the phone sees the headphones but does not connect, or the connection is constantly broken. Often the reason lies in the crowded memory of the Bluetooth cache. To solve the problem, go to Settings → Apps → All Apps, find in the list of “Bluetooth” and click “Clear Cache” and “Clear Data.” This will reset all saved profiles and start the module again.
Another common problem is Bluetooth version conflict or interference from other devices. 2.4GHz Wi-Fi routers can interfere. Try turning off Wi-Fi while pairing or stepping away from the router. Also make sure that the headphones don't have a connection to another phone, as many models don't know how to support multipoint (simultaneous connection to two sources).
If nothing works, a radical but effective method is to completely reset your network settings, which will delete all stored Wi-Fi passwords and Bluetooth pairs, returning the network settings to factory settings, via the Advanced Settings menu → Recover and Reset → Reset Wi-Fi, mobile networks and Bluetooth.
⚠️ Note: Resetting your network settings will delete all saved Wi-Fi passwords. Make sure you remember the password from your home network to reconnect to the internet after the procedure.
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If the sound in the headphones has become quiet or the bass has gone, check the equalizer settings in the Music app or third-party players. Sometimes after the MIUI update, the sound effects settings are reset, which may not be suitable for your headphone model.
Optimizing energy consumption and stability
The constant operation of the Bluetooth module can significantly affect the autonomy of the Redmi 9. MIUI system aggressively optimizes background processes, which sometimes leads to premature shutdown of the headset for “charge saving”. To avoid this, look in the battery settings section “Activity Control” and for the Bluetooth system process (if available) or for the music application used, set “No restrictions” mode.
Also worth paying attention to is the Device Search feature on the Bluetooth menu.If you don't plan on connecting new gadgets often, this feature can be disabled after initial setup, although in modern versions of Android it is controlled automatically. Disabling the phone's visibility for other devices increases security and slightly reduces power consumption.
Regular updates to the phone’s firmware are critical to the stability of wireless modules. Xiaomi engineers periodically release patches that fix bugs in Bluetooth drivers. Check for updates in the About Phone section by clicking on the MIUI version. Make sure that the battery is at least 50% before upgrading to avoid interrupting the process.
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Connection stability depends not only on the quality of the headphones, but also on the MIUI energy saving settings. Disabling aggressive optimization for music applications often solves the problem of spontaneous breaks.