The situation when during an important conversation the interlocutor becomes barely distinguishable and the words are drowned in interference, is familiar to every smartphone owner. Especially offensive when it happens on Xiaomi devices, which are famous for their functionality, but sometimes require fine-tuning of the audio track, the problem can be hidden in both banal dirt in the dynamics and software failures of the MIUI or HyperOS operating system.
Before you bring your gadget to the service center, you need to do your own diagnostics, and often it's because of a mis-exposed noise reduction setting or a physical obstacle in the way of a sound wave, and in this article, we'll look at all the possible causes of quiet sound and how to fix them, from simple cleanings to engineering menus.
Ignoring the issue can lead to you missing important information or having to constantly ask questions, which is annoying to both parties. The speaker is a complex mechanism, and its operation depends on many factors, including software and hardware condition. Let's figure out how to restore your Xiaomi to its original volume and clarity of voice.
Primary diagnosis and cleaning of the dynamics
The most common reason Redmi or Poco is not audible is because of contamination of the speaker, and the dust, the pile of the pockets, and the skin fat eventually form a dense plug that physically blocks the output of sound, and even if the grille looks clear, the microparticles can clog the membrane.
To clean, use a soft toothbrush or a dry cotton swab. Carefully, without much pressure, walk through the top speaker area. You can use a special sticky tape or "liquid" to clean the technique that pulls dirt out of hard-to-reach places. It is important not to use sharp objects such as needles or pins, as you risk damaging the safety net or the membrane itself.
If things haven't improved after mechanical cleaning, try using the "push" method of sound. Turn on the low-frequency audio file at maximum volume and hold the phone with the speaker to the open window, or just leave it for a few minutes. Vibration can help knock out stuck dust particles.
It's also worth checking if the safety glass or the cover is disturbing the sound. Some accessories, especially thick or improperly installed, can block the sound hole. Remove the cover and check the volume again. If the sound is better, the problem is solved by replacing the accessory.
⚠️ Warning: Never attempt to clean the speaker with compressed air from a high-pressure canister.A powerful jet can damage the speaker's inner membrane or drive dust even deeper inside the housing, leading to irreversible consequences.
☑️ Cleaning the dynamics
Set up sound profiles and equalizer
MIUI and the newer HyperOS have advanced audio management tools, often by accident activating modes that are not suitable for voice calls, or simply unaware of the existence of individual profiles, and setting up an equalizer allows you to highlight the frequency range of human speech.
Go to the sound settings and find the "Sound Effects" or "Sound Customization" section, where you can choose the "Voice" or "Read" profile if available, or manually adjust the equalizer. To improve the audibility of the interlocutor, it is recommended to slightly raise the sliders in the mid-frequency range (about 1-3 kHz), where the basic speech information lies.
Special attention should be paid to the functions of Dolby Atmos or Dirac, if supported by your model. These technologies can both improve and worsen speech intelligibility depending on the presets. Try to switch the modes of "Music", "Cinema" and "Voice" during a conversation to find the best option.
Remember that settings may be disrupted after you update your system, check periodically to see if the system notifications are silent or soundless, which sometimes affects the volume of the call, and check to see if the Mono-audio feature is enabled, which in some cases can make the sound quieter.
Secret codes for sound testing
If you’re using a headset or connecting your phone to your car via Bluetooth, the equalizer settings can be applied separately for each device. Make sure you adjust the settings specifically for the phone’s main speaker, not for an external accessory.
Using an engineering menu to amplify sound
For advanced users who want to get maximum control over their Xiaomi audio track, there is access to an engineering menu. Here you can manually raise the maximum speaker volume, which is limited by default by the manufacturer to protect the hearing and speaker.
To get to the menu, open the "call" and enter the combination ##3646633##. If the standard code does not work (often found in global versions), try the codes ##4636## or ##6484##. In the menu that opens, go to the Hardware Testing -> Audio -> Audio Debug tab.
You'll need to find the volume setting in talk mode, usually Speech or Call. Select the speaker type (Receiver, Speaker, speaker), select the maximum value (usually 6 or 7) in the Level field, and set the maximum value (for example, 160 or 255, but do not exceed 200, so as not to burn the speaker).
| Parameter | Description | Recommended value | Risk |
|---|---|---|---|
| Level | Volume level (step) | 6 or 7 (Max) | Low. |
| Value | Actual volume | 140-160 | Medium. |
| Digital Gain | Digital Strengthening | Not more than 12dB | High-pitched |
| Analog Gain | Analog reinforcement | Leave it by default | critical |
After making changes, be sure to press the Set button to save the settings. Then check the sound. If there are wheezing or distortions, immediately reduce the value of Value. Be careful: mishandling these settings can cause the speaker to fail.
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Changing the parameters in the engineering menu removes software volume restrictions, but requires caution not to damage the hardware part of the speaker.
The Impact of Third-Party Apps and VoIP
Often, the problem of quiet sound does not arise in the standard “bell ringer”, but in applications for Internet calls such as Viber, Telegram, WhatsApp or Zoom. These applications use their own audio compression codecs and can conflict with the system settings of Xiaomi noise reduction.
In each app's settings, look for the "Sound" or "Calls" section, check if it's turned on "Mic Dim" or "Color" or "Down" and check the permissions, which means that the app needs to have access to the microphone and, in some cases, the phone.
Android has a "Absolute Volume" feature for Bluetooth devices, which sometimes affects the software volume control in VoIP. If you notice that messengers are quieter than on a regular network, try updating the application to the latest version or reinstall it.
Also, background processes can intercept audio streams, so if you have a navigator, a music player, or a game running while you're on a call, they can "press" the voice of the other person, and close all the extra apps from memory before an important conversation.
Network problems and SIM-card
Sound quality is directly dependent on the quality of the cellular signal. If you're in an unstable reception zone, the phone can switch between 2G, 3G and 4G/LTE standards, causing interruptions and volume reduction. VoLTE (Voice over LTE) technology provides better sound, but requires support from the operator.
Check the network settings in the Settings section -> SIM-maps and mobile networks. Make sure the network type is set to "Preferred" 4G" or "5G". If you're in your area 4G If you catch a bad catch, the phone can jump between standards all the time, which makes the connection worse "3G/2G" Stability, even if the internet speeds drop.
It is also worth paying attention to the state of SIM-If it's been in use for many years, the contacts could have oxidized, and the Nano-SIM clipping could have been done sloppy, touching the chip. SIM-If the card is very old, replace it in the operator's cabin.
Some users have noted that setting custom APNs for the Internet can indirectly affect the stability of voice calls over the Internet. If the problem is only in messengers, try resetting the access point settings to factory ones.
⚠️ Warning: Metallic cases or magnetic fastener cases can interfere with smartphone antennas, significantly reducing signal strength and sound quality.
Resetting and system update
If software failures accumulate, audio drivers may not work properly, in which case resetting all settings to factory helps.This action will delete all your data, so be sure to back up contacts and photos before you start.
To reset, go to Settings -> Advanced Settings -> Recover and Reset -> Reset. After this procedure, the phone will return to the out-of-the-box state, and all system bugs affecting sound should disappear.
Also check for system updates. Xiaomi engineers regularly release patches that fix errors in the modem and audio subsystem. Go to Settings -> About the phone and click on the system version. If an update is available, install it.
In some cases, resetting your network settings (not completely resetting your phone) will help, and it will return to the factory settings of Wi-Fi, Bluetooth and mobile networks, but it will save your personal files, and you can find this option in the Connections and Sharing section or by searching the settings for Wi-Fi, Mobile Internet and Bluetooth Reset.
Hardware malfunctions and repairs
If no cleaning, no settings, no resetting has worked, and the phone is still hard to hear, it's likely that the problem is hardware-based, and it could be the failure of the speaker itself, the plume or the audio codec on the motherboard.
A common cause of quiet sound after falling or getting moisture is the plume of the speaker, which requires disassembling the device and reconnecting the connector, and it is not recommended to do this yourself if you do not have experience, since it is easy to damage other components.
The speaker membrane could also be damaged, and it might be invisible, but when the signal is given, it won't fluctuate at the right amplitude, and then it's only going to help if you replace the speaker with a new original or quality speaker.
If the phone was flooded with water, even if it worked, it could cause corrosion inside, and over time, the oxides would corrode the contacts, and the sound would disappear or become very quiet, and then you would need to ultrasonically clean the board at the service center.