Clean speaker on Xiaomi Redmi 9: how to turn on and configure the function

Why you need to clean speakers and how it works on the Redmi 9

Xiaomi’s smartphone speakers get clogged with dust, skin particles and fine debris over time, causing sound distortion, volume dimming or complete noise choking during calls. The automatic speaker cleaning feature on Redmi 9 is designed to solve this problem without disassembling the device. It works by vibrating the membrane at a certain frequency, which pushes pollution out of the grille.

Unlike flagship models, where cleaning is scheduled, the Redmi 9 needs to be manually activated, either through a hidden menu or through third-party apps. It's important to understand that this is not a panacea: if the speaker is heavily clogged (for example, after falling into the sand), mechanical cleaning in the service center will be more effective, but for the prevention or elimination of mild contamination, the built-in function will cope with "excellent".

The manufacturer does not advertise this feature, so many users do not even know it exists. Meanwhile, the correct use of cleaning can extend the life of speakers by 30-50% – especially for those who often talk on the phone in dusty conditions (construction sites, streets of metropolises, production halls).

Preparing a smartphone before cleaning the speaker

Before you start the procedure, make sure your Redmi 9 is ready to be manipulated.

• 🔋 Battery charge is at least 30%. Cleaning takes 1-2 minutes, but it is better not to risk - a sudden shutdown during the process can lead to a failure of the sound system.
• 🔇 Turn off your headphones (wired or Bluetooth) if they're connected, the cleaning will either not start or go idle.
• 📴 Close all applications that use a microphone or speakers (calls, music, games) and may interfere with active sound processes.
• 🌡️ The temperature of the body should not exceed 40°C. Overheating may distort cleaning results or cause error.

Pay special attention to the speaker grille, if it is deformed (for example, after a blow) or filled with sticky substances (sweet drinks, tar), automatic cleaning may not work, in such cases it is better to contact the service.

Method 1: Cleaning through the engineering menu (no root)

The most reliable method is to use a hidden engineering menu, which is available on all Xiaomi smartphones based on MIUI. For Redmi 9, the path to the function looks like this:

1. Open the Phone app and enter the combination: ##36446337## (code for speaker test).
2. The Engineer Mode menu will appear on the screen. Select the Hardware Testing section.
3. Scroll down to Audio point → LoudSpeaker (or Receiver if you clean the top speaker).
4. Press Speaker Cleaning and confirm the start. It takes ~90 seconds.

If the code doesn’t work, try an alternative:

#4636## → “Testing” → “Audio” → “Cleaning the Dynamics”

On Redmi 9 with MIUI 12.5 firmware and later, the feature can be hidden under another name - look for Speaker Test or Audio Tuning. If the menu is in English, use a translator or focus on icons (speaker + brush).

Headphones and Bluetooth devices are disabled

All audio applications are closed

Battery charge ≥ 30%

The phone didn't overheat.-->

Method 2: Apps to clean speakers from Google Play

If the engineering menu seems complicated, you can use third-party utilities that mimic the speaker's vibration at frequencies that push out dust.

• 🎵 Speaker Cleaner (from Smart Cleaning Apps) – supports customization of cleaning frequency and duration.
• 🔊 SoundAbout – a universal application for testing sound with the option of cleaning.
• 📱 Phone Doctor Plus – includes cleaning speakers in a comprehensive test device.

Instructions for use (for example, Speaker Cleaner):

1. Download and install the app from Google Play.
2. Start it and select the speaker type: Lower Speaker (bottom) or Earpiece (top).
3. Press Start Cleaning and wait until the end (usually 2-3 cycles of 30 seconds).
4. After cleaning, check the sound by calling another phone or turning on music.

⚠️ Note: Some applications request access to special features (Accessibility). Do not provide it unnecessarily - this may threaten data security.

What to do if cleaning does not help: alternative methods

If the sound is still distorted or quiet after the procedure, the problem may be deeper than just dust.

• 🔧 Mechanical damage: If the speaker cracks after falling, its membrane could deform.The solution is a replacement in the service (cost for the Redmi 9: ~1 200–1 800 ₽).
• 💧 Liquid intake: Even after drying, oxidized contacts can disrupt sound.
• 🔊 Software glitch: Reset the sound settings through Settings → System system → Resetting settings → Resetting the sound settings.
• 📱 Factory marriage: if the phone is new (up to 1 year), contact the warranty. For the Redmi 9, the typical defect is the detachment of the lower speaker membrane.

You can use an external speaker or a headphone to make a temporary solution, and if you're having a problem with the upper speaker, check it for contamination of the mesh, and you can clean it with a soft toothbrush soaked in alcohol.

How often should you clean the speakers on Redmi 9?

The cleaning frequency depends on the operating conditions of the smartphone. Here are some guidelines:

• 🏙️ Urban conditions (office, house): 1 time in 6 months.
• 🏗️ Dust/contaminated sites (construction, production): 1 time in 2-3 months.
• 🌊 Wet climate or frequent temperature changes: 1 time in 4 months (risk of condensation inside the enclosure).
• 🚗 Use in the machine (vibrations) + dust: 1 time in 3 months.

Signs that it is time to clean the speakers immediately:

• The sound became "booming" or wheezing.
• The volume at the maximum is noticeably lower than before.
• When calling, the interlocutor complains that your voice is “not heard” (the microphone or upper speaker is clogged).

Do not over-sweep: frequent vibrations at high frequencies can accelerate the wear of the membrane. The optimal is to combine automatic cleaning with mechanical prevention: once a month blow the speaker grille with compressed air (a canister for cleaning equipment).

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After cleaning the speakers, restart the phone - this will reset the sound driver cache and improve the result.

Precautions: What not to do when cleaning

The wrong actions can permanently disable the speakers.

⚠️ Warning: Never use sharp objects (needles, toothpicks) to clean, which pierce the membrane, and you can't blow into the speaker with your mouth, saliva and bacteria will only exacerbate pollution.

• 🚫 Water or liquids: even a drop can cause corrosion of contacts.
• 🚫 Vacuum cleaner: creates static electricity that damages electronics.
• 🚫 Cleaning at low temperature (below) +10°C): the membrane becomes brittle.
• 🚫 Using high-pressure compressed air (such as a paint compressor) – can tear off the membrane.

If you decide to disassemble your phone for deep cleaning, turn off the battery 10 minutes before work begins. This will prevent short circuits from accidentally touching the contacts. Redmi 9 will require a plastic blade and a T3 screwdriver - do not use metal tools!

FAQ: Frequent questions about cleaning speakers on Xiaomi Redmi 9

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Cleaning the speakers on the Redmi 9 regularly prevents 70% of sound problems, and the key is to keep your head down and take precautions.