How to increase the volume in headphones on Xiaomi Redmi 9S: from standard settings to hidden features

Xiaomi Redmi 9S is a popular budget smartphone with good sound, but sometimes owners face the problem of too quiet volume in the headphones. This can be due to MIUI limitations, faulty connector, incorrect settings or even firmware features. In this article, we will discuss all working ways to increase volume, from basic to advanced, including hidden functions of the engineering menu and the safe use of third-party utilities.

It is important to understand that artificially raising the volume above factory limits can cause sound distortion or even damage to the earphone speakers. So before you start settings, check the health of the headphones themselves (test them on another device) and the cleanness of the 3.5 mm jack on your smartphone. If the problem persists, follow our instructions.

1. Check basic sound settings in MIUI

Before digging deeper, make sure the system doesn't activate volume limits.The Xiaomi Redmi 9S has a few places where these settings can be reset:

• 🔊 Do Not Disturb Mode: Check if it is enabled in the top curtain or in Settings → Sound and vibration → Don't disturb.
• 🎵 Volume Limit for Multimedia: Go to Settings → Sound and vibration → Volume and move the slider to maximum.
• 📱 Sound Profiles: In some firmware MIUI have separate headphone profiles – make sure you choose Music or Games, not Conversation".

It is also worth checking whether the Adaptive Sound function is activated (in some versions). MIUI It automatically turns the volume down in the headphones. It turns off in Settings. → Special facilities → Sound. → Adaptive sound.

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If after connecting the headphones, the volume drops sharply, try to remove and insert the plug again - sometimes the smartphone incorrectly determines the type of connected device.

2.Use of uniform volume distribution (Dolby Atmos)

The Redmi 9S supports Dolby Atmos technology, which not only improves spatial sound, but also allows you to fine-tune the volume.

1. Go to Settings → Sound and vibration → Sound effects.
2. Select Dolby Atmos (if you don’t have the option, upgrade your MIUI or check the firmware region).
3. Turn on the Music or Movie mode and adjust the Dynamic Range slider towards Wide.

This feature distributes sound frequencies more evenly, which subjectively increases volume at low and medium levels. However, in some firmware, Dolby Atmos only works with Bluetooth headphones - wired ones may require additional tuning.

3. Engineering menu: hidden settings for sound amplification

If standard methods don't work, you can try changing the sound settings through the Engineering Mode, which is a hidden section of MIUI that stores low-level hardware settings, and be careful, because the wrong changes can cause failures.

To open the engineering menu:

1. Open the Phone app.
2. Enter the combination: ##36446337## (or #4636## for older versions of MIUI).
3. Go to the Hardware Testing → Audio section.

Here we are interested in two parameters:

• 🔧 Headset Mode – Select Normal Mode (if Safe Mode is required, the volume is artificially low).
• 📈 Headset Volume – Increase to 150 (default maximum: 100).

Do not change the settings in the Modem and RF partitions.

Write down the initial values before changing

Do not raise the headset volume above 150 (risk of distortion)

Reboot your phone after the changes-->

4. Third-party applications for sound amplification

If the software methods don't work well, you can use specialized applications that work as an intermediate amplifier, processing sound before you put it on your headphones. 9S:

• 🎧 Volume Booster GOODEV — A simple booster with presets for different types of headphones.
• 🔊 Equalizer FX — In addition to the amplifier has a 10-band equalizer, which allows you to raise the volume at individual frequencies.
• 📱 ViPER4Android — It's the most powerful tool, but it requires installation through Magisk, and it supports profiles for different genres of music.

When using boosters, remember:

⚠️ Attention: Amplifiers add more CPU load and can cause delays in games or videos, and they drain the battery faster on Redmi. 9S With its modest 5020mAh battery, it's noticeable.

To install ViPER4Android on a non-rooted smartphone, you can use the bypass through ADB:

1. Download APK from the official ViPER website.
2. Connect your phone to your PC and execute the command: adb shell pm grant com.pittvandewitt.viperfx android.permission.WRITE_SECURE_SETTINGS
3. Install drivers through the app and restart the device.

Volume Booster|Equalizer FX|ViPER4Android|Other|I don't use it.-->

5. Hardware causes of low volume

If software methods don't work, the problem may be hardware, and here are the most common hardware reasons for the quiet sound on the Redmi 9S:

• 🔌 3.5mm contaminated connector - dust or oxidation of the contacts leads to a poor connection.
• 🎧 Damaged headphone plug – check if there are no cracks on the wire or corrosion on the plug contacts.
• 🔊 Sound chip malfunction – if the sound is quiet in both the speaker and the headphones, the Qualcomm amplifier may have failed WCD9375 (redmi 9S It is used by Qualcomm audio codec).
• 🔋 Weak power amplifier - with a discharged battery (<15%) MIUI automatically reduces volume to save energy.

To diagnose hardware problems:

1. Connect the headphones to another device – if the sound is normal, the problem is in the smartphone.
2. Try other headphones (preferably with a low impedance – 16-32 ohms).
3. Check the sound through Bluetooth headphones – if the volume is normal, the problem is in the 3.5 mm jack.

⚠️ Warning: If the sound is gone after cleaning the connector, you may have damaged the contacts. 9S requires soldering and may result in short circuit.

6.Alternative methods: from firmware to physical amplifiers

If none of the above has worked, radical measures remain:

• 🔄 Reflashing to custom MIUI — Some builds (e.g. Xiaomi.eu or PixelExperience) have less stringent volume limits, but this requires unlocking the bootloader and may be unwarranted.
• 🔧 Replacement of the sound chip – if the diagnosis showed a malfunction Qualcomm WCD9375, It can be soldered (the cost of repair is from 1500 rubles.).
• 🎛️ External sound amplifier – devices like FiiO A1 or iBasso DC01 connect between the smartphone and headphones and amplify the signal without distortion.

To flash Redmi 9S (codename cattail) you need:

1. Unlock the bootloader via Mi Unlock Tool (waiting can take up to 7 days).
2. Install custom recovery (TWRP or OrangeFox)
3. Swipe out alternative firmware (we recommend Xiaomi.eu Stable for a balance of stability and functionality).

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Flashing is an extreme method. On the Xiaomi Redmi 9S, this voids warranty and can lead to IMEI blocking if errors occur. Always back up before firmware!

7. Frequent mistakes and how to avoid them

When trying to turn up the volume, users often make mistakes that make the problem worse.

Another common mistake is ignoring the impedance of headphones. Redmi 9S is optimized for headphones with impedance 16-32 Ohms. If you use models with impedance 64 Ohms and higher (for example, Beyerdynamic DT 770 Pro), the sound will be quiet for physical reasons - the smartphone simply can not "rock" them, in which case only an external amplifier will help.

FAQ: Answers to Frequent Questions