Connecting wireless headphones to Xiaomi Redmi 9C over Bluetooth: a complete guide with nuances

Wireless headphones have become an integral part of everyday life — they free wires, allow you to listen to music on the go and answer calls without taking your phone out of your pocket. However, even with a seemingly simple task like Bluetooth connection, Xiaomi Redmi 9C users sometimes face difficulties. From the phone does not see the device, the sound is interrupted, the headphones go off in a few minutes. In this article, we will discuss not only the basic pairing procedure, but also hidden settings that will help stabilize the connection and improve the sound quality.

The Redmi 9C, released in 2020, features a Bluetooth 5.0 module that supports most modern profiles, including A2DP (for streaming music) and AVRCP (playback control).However, the features of MIUI firmware and budget hardware limitations can create nuances. For example, some users note that after a system update, the headphones stop automatically connecting. We will tell you how to avoid this and what to do if standard methods do not work.

1. Preparation of headphones and phone for connection

Before you start pairing, make sure both devices are ready to connect, a stage that is often missed, and this is where most problems are caused.

Start with headphones. If they're new, check the charge level: most models (e.g. Xiaomi AirDots or Redmi Buds 3) require at least 30% charge for a stable connection. Some brands (e.g. Sony WH-1000XM4) have a separate pairing mode, which can be different to activate.

• 🔋 Hold the power button on the headphone case for 5-10 seconds until the indicator starts flashing blue/white (search mode).
• 🎧 For models with a case (such as Apple AirPods or Huawei FreeBuds) – open the lid and hold the button on the back.
• 📱 Make sure the headphones aren't connected to another device (like a laptop or tablet) and some models "remember" the last connection and automatically connect to it.

Now on the phone. On the Redmi 9C, it's recommended that you:

• 📵 Disable Battery Savings mode (it can limit background Bluetooth operation). path: Settings → Battery → Battery savings mode.
• 🔄 Reboot your phone if you have previously had a connection failure with other devices.
• 🛠️ Update the firmware to the latest version (relevant to the MIUI 12.5+), Because the older versions had bugs with Bluetooth codecs.

2. Step-by-step instructions: how to connect headphones to Redmi 9C

If you're done, we'll move on to pairing. The instruction is universal for most headphone models, but we'll point out the nuances for popular brands.

Step 1: Activate Bluetooth on your phone. There are two ways to do this:

• Through the notification panel: swipe from top to bottom and click on the Bluetooth icon.
• Through settings: Settings → Connections and Sharing → Bluetooth.

Step 2: Enable the headphone search mode (how to do this, we described in the previous section) The name of your headphones should appear on the phone screen in the list of available devices.

Check that the headphones are in pairing mode (blinking indicator)

Make sure that the distance between the devices is not more than 1 meter

Reboot Bluetooth on your phone (turn off/on)

Try connecting the headphones to another device (to check their performance)-->

Step 3. Click on the headphone name in the list. If required, confirm pairing on both devices (sometimes you need to press the button on the headphones or type in the headphones). PIN-code - default is 0000 or 1234).

Step 4: Wait for the message “Connected.” In some cases (such as with Sony WH-1000XM3 headphones), the phone will offer to install additional gesture control software or equalizer — this is optional, but can improve the experience.

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If the headphones are plugged in but only sounding in one channel (for example, only the left earpiece), try resetting them. This usually requires holding the power button for 15-20 seconds until the indicator flashes red/purple.

3. Customize sound and codecs for better quality

By default, Redmi 9C uses a standard SBC codec that provides basic sound quality, but if your headphones support more advanced codecs (such as AAC, aptX or LDAC), you can improve the sound.

Step 1. Open Settings → Connections and Sharing → Bluetooth.

Step 2. Find your headphones in the list of connected devices and tap the gear (⚙️) near-name.

Step 3. In the Additional Settings menu, select Sound Quality or Audio Codec (the name may vary depending on the version of MIUI).

Step 4: Choose the best codec from the available ones:

Important: Not all codecs are supported by Redmi 9C. For example, LDAC may be missing from the list, as it requires hardware support that is not available in budget models. If you choose a codec that is not compatible with headphones, the phone will automatically switch to SBC.

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For minimal audio delay (important for games and videos), choose aptX Low Latency if available, otherwise AAC is the best trade-off between quality and stability.

4. Solving common connection problems

Even after successful pairing, Redmi 9C users may face typical problems, including the most common and ways to fix them.

Problem 1: Headphones are connected, but the sound is interrupted

Reasons:

• 📶 Interference from other wireless devices (Wi-Fi router, microwaves).
• 🔋 Low battery charge headphones or phone.
• 📱 Outdated firmware MIUI or Bluetooth drivers.

Decisions:

• Move closer to the phone (optimal distance - up to 5 meters without obstacles).
• Turn off Wi-Fi on your phone (sometimes 2.4GHz channels conflict with Bluetooth).
• Reset network settings: Settings → System → Settings Reset → Reset settings Wi-Fi, mobile network and Bluetooth.

Problem 2: Headphones don’t automatically connect

This is a frequent complaint from Redmi 9C owners after a system upgrade, due to the optimization of MIUI background work, which turns off Bluetooth to save battery life.

How to fix it:

1. Open Settings → Applications → Application Management → System applications.
2. Find Bluetooth and select AutoRun → turn it on.
3. In the same menu, click Permissions and make sure all permissions are enabled.
4. Reboot the phone.

Problem 3: The sound only goes to one headphone

This problem is characteristic of TWS-Headphones (e.g. Redmi AirDots or Haylou) GT1). Causes:

• One of the headphones is discharged or faulty.
• Synchronization failure between left and right earphone.
• In the settings of the phone, Mono mode (single-channel sound) is selected.

Decisions:

• Put both headphones in the case for 10 seconds, then take out and reconnect.
• In the Bluetooth settings on your phone, check that Stereo (dual channel sound) mode is selected.
• Reset the headphones to factory settings (the method depends on the model - see the manufacturer's instructions).

⚠️ Attention: If the problem with one earphone recurs after reset, it may indicate a hardware malfunction. Check the headphones with another device (e.g. laptop).

5. Battery optimization and connection stability

Bluetooth is one of the main power consumers on the Redmi 9C, especially if the headphones are connected all the time.To extend your running time and avoid connection breaks, follow these tips:

• 🔋 Turn off your headphones when you're not using them. Even when you're on standby, they consume up to 5 to 10 percent of your phone's charge per hour.
• 📴 In Bluetooth settings, disable Visibility for all devices if you don't need it.
• 🔄 Regularly (every 1-2 months) “forget” the device and reconnect it. This clears the Bluetooth cache and prevents the accumulation of errors.
• 🛡️ Use branded headphone apps (like Mi Headphones for Xiaomi or Sony Headphones Connect devices) that optimize the connection and offer additional features like equalizer setup.

Redmi 9C has a hidden feature called Adaptive Bluetooth, which automatically reduces the bitrate of sound when the signal is weak. To turn it off (and get a more stable, but less high-quality connection), type the code ##4636## in the Phone app, select Phone Information → Bluetooth and turn off the option called Adaptive Bitrate.

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If you listen to music in transport often, turn on Street Sound (if you have one) in your headphone settings, which will reduce the load on Bluetooth by reducing the sound quality, but the connection will be more stable.

6. Alternative ways to connect headphones

If Bluetooth refuses to work consistently, consider alternative connectivity options that are less convenient, but sometimes save you in critical situations.

Connection through AUX-cable (3.5 mm)

The Redmi 9C is equipped with a headphone jack, so you can use wired headphones or a wireless adapter (if they support wired connection).

• 🎵 No sound delays.
• 🔋 No battery of headphones is consumed.

Cons:

• 🚫 Limited freedom of movement.
• 🎧 Not all. TWS-Headphones support wired connection.

Connect via USB-C (for headphones with Type-C)

Some modern headphones (for example, Xiaomi Type-C Earphones) connect directly through the USB-C port.

• 🎵 Sound quality is better than Bluetooth (lossless transmission).
• 🔋 Charging headphones directly during use.

However, this method is suitable only for headphones with the appropriate connector.

Use of the FM-transmitter

If you have an old FM-enabled headphone, you can use an FM transmitter that connects to your phone via AUX or Bluetooth. The phone will transmit sound to the frequency that the headphones catch. The downside is the low quality of sound and interference.

⚠️ Note: When connecting through AUX or USB-C Turn off Bluetooth on your phone to avoid audio route conflicts, otherwise the sound may be sent to both devices at the same time or interrupted.

7.Comparison of Bluetooth headphones for Xiaomi Redmi 9C

Not all headphones work equally well with the Redmi 9C. We tested several popular models and compiled a compatibility table:

The best choice for the Redmi 9C is headphones on a Qualcomm chip (such as Xiaomi AirDots or Haylou GT2), as they are optimized for aptX and have minimal latency. Apple AirPods headphones, although connected, can work unstable due to the peculiarities of the AAC protocol on Android.

8. Frequent questions and answers