How to increase the volume of headphones on Xiaomi Redmi Note 9S: safe and risky methods

Why are the Redmi Note 9S headphones playing too quiet?

Owners of Xiaomi Redmi Note 9S often face the problem of low volume in wired and wireless headphones. the reasons can lie in both hardware limitations of the smartphone and in the software settings of MIUI. For example, European versions of firmware artificially lower the maximum volume level due to EU regulations (directive 2003/10/EC), and in some cases, bad contact in the 3.5 mm connector or incorrect Bluetooth drivers is to blame.

It's important to understand that quiet sound isn't always a defect in the device. The manufacturer deliberately limits the volume to protect users' hearing from damage during long-term listening. However, if you're sure that the problem isn't with the headphones (check them on another device), you can try to increase the volume by software methods. Next, we'll look at all the working methods, from safe to those that require caution.

Before you start settings, make sure that:

• 🔊 Headphones are clean (no blockages in the speakers or connector)
• 🔌 Wired headphones are tightly inserted into the 3.5 mm connector (try to slightly move the plug)
• 📱 There is no active "Do Not Disturb" mode or "Meeting" profile on the smartphone"
• 🔋 Battery level above 15% (at low charge) MIUI automatically reduces volume)

Method 1: Sound settings in MIUI (Safe Method)

The easiest and safest way to do this is to use the built-in MIUI 12/13/14 tools, which may vary slightly depending on the firmware version, but the general logic is maintained.

1. Open the Settings. → Sound and vibration.
2. Slip the Media slider and move it to the far right.
3. Activate the Volume Amplifier option (if available in your MIUI version).
4. Check if the Adaptive Sound mode is on – it can automatically turn down the volume in noisy rooms.

If the standard slider does not give a sufficient level, try to turn on the sound effects:

• 🎵 Go to Settings. → Sound and vibration → Sound effects.
• 🔊 Choose a preset called "Bas" or "Rock" - they amplify the low frequencies, which subjectively makes the sound louder.
• 🎧 Activate "3D-"Sound" (if available) - This creates a volumetric effect, but may distort the original sound.

Important! In some regional firmware (e.g. EU), the Volume Amplifier option is hidden. To unlock it, you will need to change the device region to India or the Global version through Settings → Additional → Region.

Method 2: Engineering menu (for experienced users)

If the standard settings did not help, you can refer to the engineering menu (MTK Engineer Mode or Qualcomm Diag). Redmi Note 9S is equipped with a Qualcomm Snapdragon 720G processor, so we will suit the method for Qualcomm chipsets.

Instructions to increase volume through the engineering menu:

1. Open the Phone app and enter the code: ##36446337## (if the code doesn't work, try ##4636## → Phone Information → Select Test Type → Audio).
2. In the Hardware Testing menu, select Audio.
3. Go to the "Headset Mode" tab.
4. Set the settings: "Max Vol" - increase the value from 84 to 100. "Type" - select "Class AB" (gives more power, but heats the chip). "Gain" - set +6 dB (no more, otherwise there will be distortions!).

Save the settings and restart the smartphone.

⚠️ Note: Increase in Max Vol above 100 or Gain above +6 dB can damage the earphone speakers or overheat the audio chip in the smartphone (+2 dB) and gradually increase.

Method 3: Applications for sound amplification

If you don't want to dig into the settings, you can use third-party apps. They work as an intermediate amplifier, processing sound before you output it to your headphones. 9S:

The most common option is Volume Booster:

1. Download the app from Google Play.
2. Start and move the Boost Media Volume slider 120-150 percent.
3. Activate the “Prevent Distortion” option to reduce distortion.
4. Turn on the music and check the sound.

ViPER4Android is a more advanced solution, but requires additional actions:

• 📥 Install. ViPER4Android (APK + driver).
• 🔧 Select “Audio Compatibility Patch” and install the driver.
• 🎛 Turn on Master Limiter and raise Gain to +3 dB.
• 🔄 Reboot your smartphone.

⚠️ Attention: Amplifiers don't increase the actual power of the audio chip, they only process the sound in software:

• 🔥 Overheating of the processor during prolonged use.
• 🔊 Distortion of sound (wheezing, crackling) at high frequencies.
• 📵 Quick battery discharge (up to 15% per hour of listening).

💡

Before using sound amplifiers, check the headphones on another device — perhaps the problem is with the speakers themselves, not the smartphone.

Method 4: Change the file mixer_paths.xml (advanced)

This method requires an unlocked bootloader and root rights, but gives you maximum volume control. mixer_paths.xml It's a chip that has the configuration of the audio chip, and editing it allows you to remove the software constraints!

Step-by-step:

1. Get root rights (for example, through Magisk).
2. Install a file manager with root support (such as Root Explorer).
3. Cross the path: /vendor/etc/mixer_paths.xml Make a backup copy of the file!
4. Find the lines with the options for headphones (look for headset or headphone).
5. Change the rx-vol values (e.g., from 84 to 95). Example: <path name="headphone"> <ctl name="RX1 Digital Volume" value="95" /> <ctl name="RX2 Digital Volume" value="95" /> </path>
6. Save the file, set the rights 644 (rw-r--r---).
7. Reboot your smartphone.

If the sound is lost or there is a distortion after the changes, return the original file from the backup. Also note that after the MIUI update, all changes will reset.

💡

Editing mixer_paths.xml — The most effective way to increase volume, but it requires root and can cause you to lose warranty.

Method 5: Hardware solutions (if software solutions do not help)

If none of the software methods worked, the problem could be in the hardware.

• 🔧 Clean 3.5mm connector: Use toothpick or compressed air to remove dust. Do not use metal objects!
• 🔄 Replacement of connector: If the contact is bad (sound only appears when the plug is in a certain position), the solder may have gone away. ₽.
• 📶 Bluetooth problems: For wireless headphones, try resetting the module settings: Go to Settings → Connected devices → Bluetooth. Remove all paired devices. Turn off Bluetooth, reboot your smartphone, and pair your headphones again.

Reset to factory settings:

If you suspect an audio chip malfunction (e.g., the sound is distorted even at a minimum volume), contact the service center. 9S It has a separate Qualcomm audio codec. WCD9375, It'll cost you 1500 to 2,500 to replace it. ₽.

⚠️ Warning: If you solder a 3.5 mm connector by an inexperienced master, you can damage the tracks on the board. If the smartphone is warranty, do not open it yourself - this will void the warranty obligations.

Comparison of methods: what to choose?

To make it easier for you to determine, we have compiled a comparative table of all ways:

For most users, the best solution will be a combination of settings. MIUI + Amplifier app (like Wavelet for Bluetooth headphones) If you want maximum volume and you're willing to take a chance, try an engineering menu or edit. mixer_paths.xml.

FAQ: Frequent Volume Update Questions on Redmi Note 9S