Why Redmi 9C NFC has a quiet sound and how to fix it
Owners of Xiaomi Redmi 9C NFC often face the problem of insufficient loudness of speakers, especially when listening to music, watching videos or while calling. The reasons can be several: from basic system settings to hardware limitations of the budget model. It is important to understand that the Redmi 9C NFC is equipped with one bottom speaker with a power of 0.5 watts, which is objectively weaker than the flagship solutions with stereo sound.
Before you start taking drastic measures (such as disassembling your phone or flashing it), it is worth checking the software settings. In 80% of cases, the problem is solved without interference with the hardware. In this article, we will analyze all the available methods, from obvious to hidden MIUI functions that Xiaomi does not advertise. Particular attention will be paid to security: some methods can lead to overheating of the speaker or distortion of the sound.
If you've been using your phone for less than a year, check if the volume drop is due to a pollution of the speaker (dust, pile) or mechanical damage, and you just need to shine a flashlight into the speaker's grille, and the visible particles indicate that you need to clean.
1. Basic volume settings in MIUI
Start by checking the standard regulators. Redmi 9C NFC has separate sliders for media, calls and alarms that often get lost after updates or resets. Here's how to set them up correctly:
- Open the Settings. → Sound and vibration.
- Slip on Volume (or press physical volume buttons and select Settings).
- Check all three sliders: 🔊 Media - music, video, games; 📞 Calls - volume of conversations; ⏰ Alarm clock - alert signals.
Notice the option "Silent mode" at the top of the screen — sometimes it's activated accidentally. You can also turn on "Scale up" when you press the buttons, which will add tactile feedback when you adjust.
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If the individual volume sliders are missing after the MIUI update, try resetting the sound settings: Settings → Applications → Application Management → Three dots (menu) → Reset the application settings.
Activation of the "Sound Amplifier" mode (hidden MIUI function)
MIUI 12+ firmware for Redmi 9C NFC has a hidden audio amplification mode that is not displayed in the standard menu, and can be enabled via an engineering menu or a special code:
##36446337##After you enter, the EngineerMode menu will open. Go to Hardware Testing → Audio → LoudSpeaker Mode.
The parameters are available here:
- 🔇 Normal Mode – Standard Volume;
- 🔊 Loud Mode - reinforcement on 20-30%;
- 🚨 Headset Loud Mode – Maximum gain (risk of distortion!).
Do not turn on for a maximum of 10 minutes | Check the temperature of the phone (not higher than 40 ° C) | Turn off when wheezing in the speaker | Do not use with Bluetooth devices
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⚠️ Warning: Headset Loud Mode can cause the speaker to burn out over long periods of use. Test it only with short audio files (up to 1 minute).
3. Equalizer and sound effects setup
MIUI has a built-in system equalizer that many users ignore, and the right settings can add up to 15 percent subjective volume by raising high and medium frequencies.
- Open Settings → Sound and vibration → Sound equalizer.
- Choose Preset Rock or Pop, which raises the average frequencies, making the sound "closer".
- Hand-lift the sliders: 🎛️ 300 Hz - 1 kHz: +3...+5 dB (voice, bass guitar); 🎛️ 4 - 8 kHz: +2...+4 dB (clearness, "air").
For music in headphones, activate Mi Sound Enhancer, which will add virtual environments, but for an external speaker, this effect often makes the sound more deaf.
Standard (unchanged) |Rock/Pop|Castom settings |Disconnected |I don't know what it-->
| Preset equaliser | The effect on volume | Better for you. | Risk of distortion |
|---|---|---|---|
| Rock. | +10-15% | Music, movies | Medium. |
| Classic. | +5% | Voice recordings | Low. |
| Bass. | -5% (subjectively) | Electronics, hip-hop | High-pitched |
| Custom (4-8 kHz +4 dB) | +20% | Speech, podcasts | High-pitched |
Bluetooth problems: why the sound is quieter than over the wire
Many Redmi 9C NFC users have noted that the sound through Bluetooth headphones or speakers is noticeably quieter than when wired, due to the limitations of the Qualcomm Snapdragon 662 chip and the SBC protocol (standard Bluetooth codec).
- 🔗 Use the codec. AAC: Connect the device; Open the Settings → Connected devices → Settings (cog next to the device) → Sound quality; Choose AAC instead SBC.
- 📱 Update the firmware of the Bluetooth module: Go to Settings → The phone. → Version. MIUI Check the relevance of the updates.
- 🔊 Turn on "Absolute Volume" (requires unlocked bootloader): Activated via ADB-command: adb shell settings put global bluetooth_absolute_volume_enabled 1.