The problem of quiet or hoarse sound when talking is one of the most common defects faced by owners of smartphones Redmi series. owners of the model Redmi Note 8 often complain that the interlocutors stop hearing them or hear intermittent sound, making using the device for business negotiations almost impossible.
The reasons for this behavior can be found in software failures of the MIUI operating system, as well as in physical contamination or hardware breakdown of sensitive elements. Before carrying the gadget to the service center, you should try to perform a number of settings and diagnostic procedures yourself.
In this article, we will look at all the available methods that will help you restore normal sensitivity and clarity of voice transmission without the need for a complete replacement of equipment.
Diagnostics and cleaning of the hardware
The first step is always visual inspection and physical cleaning of the device, often solved by simply removing dust, pile or dirt that has been accumulating for years in the grid of the main microphone located on the bottom end of the case.
Use a soft brush or soft bristles toothbrush to gently sweep out contaminants.Do not use sharp objects such as needles or pins, as you risk damaging the membrane, leading to complete loss of functionality.
If you carry your phone in a case, make sure it doesn't block the opening for sound entry. Sometimes even a minimal shift of the security accessory can create a jamming effect, making your voice barely audible to the interlocutor.
⚠️ Attention: It is strictly forbidden to use high-pressure compressed air to blow holes. A powerful jet can push the microphone's protective membrane into the housing, after which it will be impossible to restore it.
You can use isopropyl alcohol to clean it more thoroughly, by applying it to a cotton swab and squeezing it out a little bit, and then you can walk around the grid carefully, trying not to wet the speaker or the other parts of the board.
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Use your phone’s flashlight to illuminate the microphone hole at an angle – so you’ll better see dense lumps of dust that interfere with the sound wave’s passage.
Software setting and resetting of sound settings
If the physical cleaning did not work, you need to pay attention to the software part. In the Android operating system installed on the Xiaomi Redmi Note 8, there are hidden settings and parameters that affect the processing of the audio signal.
Try resetting all settings to factory settings, saving important data beforehand, and this action will return all system parameters, including volume levels and noise reduction settings, to the original state.
It’s also worth checking if the Quiet microphone mode is activated in third-party recording or calling apps, and sometimes third-party software can intercept the audio driver’s control and lower the input level.
It's important to check the noise cancellation. In some firmware, this function doesn't work properly, cutting off not only background noise, but also the speaker's voice. Try turning off additional audio enhancements in the settings.
- 🔍 Go to Settings. → Sound and vibration → Additional sound settings and disable all effects.
- 📞 Check the speaker mode: if the sound is normal, the problem may be in the upper conversational speaker.
- 📱 Make sure that there is no protective film on the screen during the conversation that covers the upper slot.
Use of the Engineering Menu for Calibration
The most effective diagnostic and tuning tool is the MIUI Engineering Menu, a hidden part of the system designed to test hardware components, including microphones.
To enter the test menu, you need to type a special code in the Phone app. Once you enter the combination, a list of available tests will open, where we are interested in the audio section.
##6484##In the CIT (Customer Interface Test) menu that opens, find the "Main Mic" or "Sub Mic" option. Select it and click "Start Test." You will be prompted to say the phrase, after which the system will evaluate the recording quality and give the result "Pass" or "Fail".
⚠️ Warning: Don't change the values in Calibration unless you know exactly what you're doing.Resetting calibration factors can cause the microphone to malfunction even with proper hardware.
If the test shows an error, try to run it several times in silence, and if the error is repeated, it indicates a deep software driver failure or a physical malfunction.
What if the code doesn't work?
Checking safe operation
Sometimes the cause of bad sound is conflicting applications that you installed recently, and messengers, voice recorders, or call recording software can create software conflicts.
To rule out this factor, run the Xiaomi Redmi Note 8 in Safe Mode, which only downloads system applications, allowing you to know if third-party software is to blame.
To enter Safe Mode, press and hold the Off button, then press and hold your finger on the Turn Off button on the screen until the prompt appears to go to Safe Mode.
After you restart, check the sound quality, and if the microphone is working perfectly in safe mode, then the problem lies in one of the applications you have installed, and you will have to remove the newly installed software by eliminating it.
| Symptoms. | Probable cause | Method of decision |
|---|---|---|
| Quiet sound only on WhatsApp | Application settings | Clear WhatsApp cache |
| Wheezing and crackling on recording | Grid contamination | Physical cleaning |
| The interviewer doesn't hear at all. | The plume break | Replacement of microphone |
| Sound, I mean, no. | Oxidation of contacts | Cleaning the charge with alcohol |
Problems with Bluetooth headsets and headphones
People often confuse the problem of the phone's microphone with the malfunction of wireless devices. If you can't hear you when talking through Bluetooth headphones, it's not always the fault of the smartphone.
Check if an external device that is not currently connected or discharged is selected as the audio input device in the application (for example, in Telegram or Viber).
Try Forget Device in Bluetooth settings and re-embed it. Sometimes an A2DP or Hands-Free Profile (HFP) profile may not work properly, requiring a full reconnection.
You should also check the permission settings. Make sure the apps you're communicating through are allowed to use the microphone. → Annexes → Permits → Microphone.
☑️ Diagnostics of Bluetooth sound
Hardware replacement: when you need rations
If all the software methods, cleaning and tests on the engineering menu have gone negative, chances are the Redmi Note 8 microphone has physically failed, a common problem, especially if the phone has fallen or come into contact with moisture.
This model uses a microphone module that is soldered to the motherboard or connected through a connector on a flexible plume (depending on the revision of the board).
To replace, you'll need a hair dryer, soldering iron, thin tweezers and a new microphone module.The process involves removing the back cover, battery and dismantling the motherboard to access the bottom.
When soldering, it is important not to overheat the fee, as the multi-layered structure of the PCB can be layered, which will lead to more complex and expensive repairs.
⚠️ Warning: Before any disassembly work begins, be sure to disconnect the battery plume from the motherboard.
The cost of the original microphone is relatively low, so replacing it is cost-effective compared to buying a new device.
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If after cleaning and software resets the engineering test shows Fail, further software configuration is useless - hardware repair is required.