How to make normal sound on Xiaomi Redmi Note 9S: from setting up the speaker to selecting headphones

Why is the sound on the Redmi Note 9S disappointing?

Xiaomi Redmi Note 9S is one of the most popular budget smartphones, but its sound system is often the subject of criticism. Users complain about the quiet speaker, distortion at maximum volume and poor playback in the headphones. The reasons lie in hardware limitations: the model is equipped with a single mono speaker with a capacity of only 0.5 watts, and the Qualcomm WCD9375 audio chip does not support advanced audio processing technologies like flagships.

However, even with these features, you can significantly improve the sound. The problem is not always the hardware — often the fault of the wrong settings, outdated software or suboptimal codec. In this article, we will discuss 7 working ways to make the sound on the Redmi Note 9S louder, cleaner and more voluminous — from basic settings to advanced tricks with MIUI and third-party applications.

It is important to understand: the speaker of the smartphone physically can not compare with a column or headphones premium, but the right settings will reveal its potential for the future. 80-90%. If you expect bass like JBL Charge -- you're going to have to accept or buy extra acoustics, but it's very realistic to make sound comfortable for listening to music, video and calls.

1. Check basic sound settings in MIUI

Before digging deep, make sure that the standard settings are not lost. Often users accidentally change the settings without even knowing it.

Settings → Sound and vibration

Please note the following points:

• 🔊 Media volume – the slider should be at its maximum (but not always good, more on this below).
• 🎵 Sound quality – select High (Balanced by default).
• 🔄 Adaptive sound – turn off this feature if you hear distortions when you change volume.
• 📱 Sound through the speaker – check if the only headphones mode is activated (occurs after connecting Bluetooth devices).

Pay special attention to the item "Sound Effects." MIUI has a built-in equalizer, but it's hidden: to turn it on, you need to:

1. Go to Settings → Sound and vibration → Sound effects.
2. Select a User Profile.
3. Manually adjust sliders for low, medium and high frequencies (we recommend starting with +2 dB on bass and +1 dB on high).

Set the media volume to the maximum|Select "High" sound quality|Deactivate "Adaptive sound"|Check playback mode (not "Hearphones only")|Set up the equalizer in "Sound Effects"-->

If you've done this, the sound is better, great, and if you haven't, we're going to go to more serious methods.

2. Software Update and Firmware: Why It Matters for Sound

Often, sound problems are solved by a banal system update. Xiaomi regularly releases patches that fix bugs with audio drivers. For example, MIUI 12.5 for the Redmi Note 9S was fixed bug with the loss of sound in one of the speakers when listening via Bluetooth.

To update the software:

Settings → About the phone → System update

If there are no updates, but the sound is still bad, try resetting the sound settings to factory:

Settings → System and device → Resetting settings → Resetting sound settings →

Once a month |Only when critical bugs appear |Never, everything works and so |I don't know how to do it-->

If the sound gets worse after the update (this happens!), try to roll back to the previous version of MIUI via Fastboot. The instructions can be found on the 4PDA forum in the theme of your model.

⚠️ Note: Do not install custom firmware for sound improvement if you do not understand the sound. TWRP and ADB. Incorrect firmware can disable the audio chip, and the sound will disappear completely.

3. Use of third-party equalizers and sound amplifiers

Built-in equalizer in MIUI It's a pretty primitive one. You better use third-party apps to fine-tune the sound.-3 tested:

For the Redmi Note 9S, we recommend starting with Wavelet, which is easier to set up and doesn’t require root.

1. Select the headphone profile (if you use it) or Generic for the speaker.
2. Activate Auto EQ – the application will automatically select the optimal settings.
3. In the Effects section, turn on "Bass Boost" at +3 dB and "Clarity" at +2 dB.

💡

If the sound is quieter after you set the equalizer, check if it conflicts with the built-in MIUI effects. Turn off all system audio enhancements in the phone settings.

ViPER4Android requires Magisk and additional driver manipulation, and if you're not ready to mess around, you'd better stop at Wavelet or Poweramp.

4. Sound tuning through the engineering menu (for advanced)

Redmi Note 9S has a hidden engineering menu where you can fine-tune the audio chip settings. Be careful - the wrong changes can lead to breakage of the speaker!

To get on the menu:

1. Open the Phone app.
2. Enter the combination: ##36446337## (code for MTK-chips, on Qualcomm may not work).
3. Go to the Hardware Testing → Audio section.

Here you can test:

• 🔈 Maximum volume – some firmware artificially lowers it.
• 🎛️ Channel balance – if the sound is distorted in just one speaker.
• 🔧 Microphone Sensitivity – Relevant for Calls.

⚠️ Note: Do not increase the value of Max Vol above 150 It can burn the speaker. Optimal value for the Redmi Note. 9S — 130-140.

If the engineering menu doesn't open, your firmware has blocked access. ADB-team:

adb shell am start -n com.android.settings/.TestingSettings

5. Problems with Bluetooth and wireless headphones

Many Redmi Note 9S users experience intermittent sound or low volume when connected via Bluetooth.

• 🔄 Outdated codec (used by default) SBC, compressor).
• 📶 Interference from other devices at a frequency of 2.4 GHz.
• 🔋 Energy savings limiting Bluetooth bandwidth.

To improve the sound over Bluetooth:

1. Turn on the "Developer Options" mode (7 times tap the build number in Settings → About phone).
2. Go to Settings → Additional → For developers.
3. Find the items: Bluetooth Audio Codec → choose AAC or aptX (if your headphones support). Bluetooth Audio Sample Rate → install 48,000Hz. Bluetooth Audio Bits per Sample → choose 16 bits.

Adaptive frequency Bluetooth

If the sound is interrupted, try:

• 📱 Reboot the phone and headphones.
• 🔄 Forget the device in Bluetooth settings and connect again.
• 📡 Disable Wi-Fi while listening (interference from the router).

💡

The aptX codec gives you better Bluetooth audio quality, but it only works with support earphones (like the Sony WH-1000XM4 or Jabra Elite). If your headphones don't support aptX, go for AAC, which is better than SBC.

6. Hardware solutions: from cleaning the speaker to external acoustics

If the software methods didn't work, the problem could be the physical condition of the device.

1. Contamination speaker. Dust and pile eventually clog the net, which makes the sound worse.

• 🧹 A soft brush (for example, for drawing).
• 💨 Compressed air (a canister for cleaning equipment).
• 🧲 Magnet (carefully!) to remove metallic particles.

2. Membrane damage speaker, if the sound is wheezing or gone, maybe the membrane is torn, and you can check this by flashing a flashlight into the speaker's grille, so if you see damage, you need to replace it.

3. Connect external acoustics. If you want really good sound, consider:

• 🔊 Portable speakers (for example, Xiaomi Mi Portable Bluetooth Speaker – budget option with decent sound).
• 🎧 Headphones with good noise insulation (Xiaomi Hybrid Pro) HD or Soundpeats Air3).
• 🔌 USB-C DAC (Like iBasso. DC05) for connecting wired headphones with bypassing the built-in audio chip.

If you decide to replace the speaker, consider:

• 🛠️ Original speaker for Redmi Note 9S worth ~500-700 ruble.
• 🔧 Replacement requires disassembling the phone (risk of damage to plumes!).
• 📉 After replacement, you may need to calibrate the sound through the engineering menu.

7. Alternative methods: from magnetic antenna to custom firmware

If you’re willing to experiment, here are some non-standard ways to improve your sound:

1. Magnetic speaker. Some users put a small neodymium magnet next to the speaker on the back of the phone, which supposedly increases the vibration of the membrane.

• 🧲 May damage other components (e.g., proximity sensor).
• 🔊 The effect is minimal and subjective.

2. Custom firmware. Firmware like Pixel Experience or LineageOS sometimes offer better audio optimization.

• 🔄 The loader is required to be unlocked and TWRP.
• 🚨 The risk of “bricking” the phone.
• 📵 Some functions may be missing (for example, IR-blaster).

3. Sound amplification applications like Volume Booster or Speaker Clean promise to increase volume by 20-30%.

• 🔊 Maximum +5-10% volume (due to distortions).
• 🚫 Can damage the speaker with prolonged use.

⚠️ Warning: Do not use applications that require root to overclock the audio chip.This is almost guaranteed to shorten the life of the speaker or disable it.

Yes, if it makes a big difference |No, I'm afraid to break my phone |I've tried it before, I haven't noticed the effect |I prefer external acoustics-->

FAQ: Frequent Sound Questions on the Redmi Note 9S