Modern Xiaomi Redmi smartphones come with a sophisticated sound recording system that includes not just one, but several modules. Users often wonder about the physical location of these components when faced with recording quality issues or after moisture enters the case. Understanding the device architecture helps not only in diagnosing malfunctions, but also in the proper care of the gadget.
In this article, we will discuss in detail where to look for the main and additional microphones on various Redmi models, consider their design features and learn how to independently conduct primary diagnosis without contacting the service center.
Architecture of audio system in smartphones Xiaomi
Xiaomi engineers are introducing noise reduction technology into their devices, which requires the use of at least two microphones. The main microphone is usually located at the bottom of the case, next to the charging connector or speaker, and is responsible for transmitting your voice during a conversation in standard conditions.
The second module, often called the secondary microphone, performs a noise reduction function, which cuts off background noise, allowing the interlocutor to hear you clearly even in windy weather or on a noisy street, and the location of this element varies depending on the particular model and year of release of the device.
⚠️ Warning: Trying to remove the microphone without special tools and skills can damage the plumes or violate the tightness of the case, which will deprive you of warranty.
Some of Redmi’s flagship models also feature a third microphone on the top end, which is used to record stereo video and improve the performance of Google Assistant or Xiao AI when the screen is active.
Location of the main microphone on the lower edge
In the vast majority of Redmi models, including the popular Note and K series, the main sound recording element is on the lower end of the device.
Often users mistake the speaker hole for the microphone input. In fact, in current models, the microphone hole can be hidden inside a USB Type-C or Micro-USB connector. This is done to protect the component from dust and moisture, but complicates the cleaning process.
- 🔍 Carefully examine the charging connector: inside, at one of the walls, you can notice a small circular hole.
- 🔊 If there are a number of holes next to the charging connector, it is a speaker, and the microphone can be symmetrical on the other side or inside the port.
- 🛡️ Moisture-protected models often have a microphone fully integrated into the charging port structure.
You can use a flashlight and a magnifying glass to pinpoint your location, and if you see a grid or membrane deep inside the connector, it's probably the main microphone's input.
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Use macro photography on another smartphone’s camera to take a detailed look at the insides of the charging connector and find the microphone input.
Upper end and hidden noise reduction modules
The second microphone, which is responsible for noise reduction, is traditionally located on the top end of the smartphone. In models with a 3.5 mm headphone jack, it is often integrated directly into the socket or located next to it.
In devices without a minijack (for example, Redmi Note 10 Pro, Redmi K40), this module is hidden in a barely noticeable hole on the frame of the case, sometimes it is closed with a grid, the color of which matches the color of the frame, making it almost invisible when viewed cursoryly.
| Model Redmi | Location of the main MK | Location of the second MK | Presence of a third IC |
|---|---|---|---|
| Redmi Note 9/10 | Inside USB-C | Top frame (left) | No. |
| Redmi Note 11/12 | Right of USB-C. | Top frame (right) | Yes (for video) |
| Redmi K40/K50 | Inside USB-C | Top frame (centre) | Yes. |
| Redmi 9/10C | Left of USB-C. | Next to the 3.5mm jack | No. |
The third microphone is typical of more expensive models, which allows you to record sound in Stereo format when shooting video, creating a surround effect, and it can be found on the upper end, often shifted to one of the corners.
☑️ Checking the top microphone
Microphone in the main camera module
There is a common misconception that the microphone is directly on the camera board.In fact, in some Redmi designs, the microphone module is physically located next to the camera unit on the back, but electrically and functionally it is part of the overall audio system.
This is a solution that's used to improve video recording, and when you're shooting a video, your smartphone can use this particular microphone, the third microphone, or the secondary microphone, to make the sound match the direction of the lens, which is especially true when shooting horizontally.
Diagnostics of this module is carried out through the Camera app, if the sound is quiet or intermittent when recording a video, and everything is fine when calling, the problem may lie in the rear microphone or its contacts.
⚠️ Attention: Cleaning the area of the cameras requires special care.The use of metal objects can scratch the lenses or damage the optical stabilization.
Sometimes the hole in this microphone is disguised as a design element or is in a black frame around the lenses, visually it can look like a small black dot with a diameter of less than 1 mm.
Diagnostics of the performance of microphones
Before you can carry the device for repair, you need to determine exactly which microphone is not working. The MIUI and HyperOS shells have built-in testing tools, but for deep inspection, you better use the engineering menu.
To enter the test mode, dial ##6484## in your phone. This will open the CIT (Customer Information Test) menu. Find Main Mic or Sub Mic to check the main and secondary channels, respectively.
- 🎤 Select the main microphone test and say the phrase – you should hear yourself in the dynamics.
- 🔇 Select a secondary microphone test and repeat the action; the sound may be quieter as this channel is often noise-cancelling.
- 📹 Record the video on the camera, covering the different holes with your finger to see which channel stops writing.
What if the microphone works on the engineering menu and Skype doesn’t?
If there's sound in the engineering menu but there's no sound in the apps, it's software-based, and if the test is silent or cracking, it's likely to have a hardware breakdown.
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The CIT engineering menu allows you to check each microphone separately, ignoring the system’s software filters, which gives the most accurate diagnostic result.
Cleaning and maintenance methods
Pollution of the microphone grids is the most common cause of communication deterioration: earwax, dust from pockets and tissue villi clog small holes tightly, creating an acoustic stopper.
To clean, you can not use sharp metal objects such as needles or pins, they can pierce the protective membrane, after which the microphone will start to “hritter” or completely fail due to moisture.
Recommended cleaning procedure:
1. Turn off the smartphone.
2. Use a soft toothbrush (dry).
3. Carefully pass the brush through the holes in circular movements.
4. blow with compressed air (a cylinder for cleaning optics).
5. wipe with an alcohol napkin (without pouring inside!).If the microphone is inside the charging connector, use an antistatic brush. You can also carefully use the sticky part of the tape rolled up into a flagellum to pull dust from the depths of the port.
Software settings and permissions
Sometimes the problem isn't hardware, it's privacy settings. Android has a strict control over how apps access the microphone, and if you upgraded your system or app, access could be reset.
Go to Settings → Privacy Protection → Special Permissions → Microphone. Here you will see a list of all the apps that have requested audio access. Make sure the switches for messengers and voice recorders are active.
It's also worth checking the noise reduction settings. Some versions of MIUI have a "Noise Removal" option in call settings, which can over-muffle your voice if the algorithm isn't working properly in your area.