Audio device of the Xiaomi phone: understand the sound system of the smartphone

When you listen to music, watch videos, or talk to Xiaomi, the quality of the sound is determined by a complex system of components, an audio device, a term that is often found in settings, diagnostic menus, or when looking for solutions to sound problems. But what exactly is behind this concept? Why are some instructions telling you to "check the audio device" and service centers saying "an audio track malfunction"?

In fact, a smartphone’s audio device is not just one element, but a whole group of hardware and software components working together. In Xiaomi phones (be it a budget Redmi Note or a flagship Xiaomi 14 Ultra), microphones, speakers, audio codecs, amplifiers and even special chips for signal processing are responsible for sound, and audio problems can manifest themselves in different ways, from quiet sound in the dynamics to the complete absence of microphone input during calls. In this article, we will understand what Xiaomi’s audio system is made of, how it works and what to do if something goes wrong.

What is included in the concept of “audio device” in Xiaomi smartphones

The term “audio device” in the context of Xiaomi smartphones brings together all the elements involved in recording, processing and playing sound, not only speakers and microphones, but also “invisible” components to the user.

• 🔊 Speakers are external (for media) and conversational (for calls). Modern models often use a stereo or even a 4-speaker system (for example, Xiaomi 13T Pro).
• 🎤 Microphones are the main (bottom), noise-cancelling (top) and additional for recording video. In some flagships, they number up to 4.
• 🔌 Audio codec is a chip that converts digital signals to analog (and vice versa). Xiaomi often uses solutions from Qualcomm (in Snapdragon) or MediaTek.
• 📶 Sound amplifiers are individual chips that amplify the signal for speakers or headphones. Budget models may not.
• 🔧 Software processing – noise reduction algorithms, equalizers and proprietary technologies (e.g., Xiaomi Sound Effects).

It is important to understand that problems with the audio device can be both hardware (damaged speaker) and software (failure in the driver of the audio codec). For example, if after the MIUI update the sound is lost in the headphones, the software is to blame, and if the speaker wheezes after the phone falls, it is a mechanical malfunction.

How the audio system works in Xiaomi phones: from recording to playback

To understand why there's a sound problem, let's look at how the audio signal travels through the smartphone.

1. Sound capture: Your voice is picked up by a microphone and converted into an electrical signal.
2. Digitization: An audio codec converts an analog signal to a digital one (for example, to a PCM format).
3. Processing: The processor applies noise cancellation, voice amplification, or echo suppression (in AI Noise Cancellation models).
4. Transmission: A digital signal is sent through the network to the operator.
5. Reproduction: on the side of the interlocutor, the process goes in reverse - sound is formed in the dynamics from a digital signal.

In Xiaomi phones, this process is responsible for:

• 📱 Processor (e.g. Snapdragon 8 Gen 2 in Xiaomi 13 Pro) – processes audio data.
• 🔧 Audio codec (built into a chipset or separate, as AKM in some models) is responsible for the quality of the conversion.
• 🔊 DAC/ADC (Digital Analog/Analogue-Digital Converter) is critical for sound in headphones.

Xiaomi models with Hi-Res Audio support (such as the Xiaomi 12S Ultra) use a separate high-quality DAC, which allows you to play sound with a resolution of up to 32 bits/384 kHz. If your phone supports this standard, the appropriate switch will appear in the sound settings.

Where in the settings Xiaomi to find information about the audio device

If you want to check the status of the audio system or change the sound parameters, MIUI has a few hidden and explicit menus.

1. Basic audio settings: Go to Settings → Sound and Vibration. Here you can: 🔈 Set the volume of media, calls and alarms. 🎵 Turn on the equalizer (Xiaomi Sound Effects). 🔇 Activate Do Not Disturb mode.
2. Diagnostics of audio devices: To check speakers and microphones, enter the Phone application code ##6484## (Manual Test Mode). From the menu, select Speaker for speaker test, Microphone for microphone check, Headset for 3.5 mm connector test (if any).
3. Hidden Developer Settings: Activate Settings → About Phone → MIUI Version (click 7 times). Then in Settings → Additional → For developers, find: Turn off absolute volume (helps with quiet sound in Bluetooth headphones). Bluetooth audio codec - codec selection (SBC, AAC, aptX).

⚠️ Warning: In menu ##6484##, don't click on tests unless you're sure they're intended. For example, the Vibrator Test can start vibrations at maximum power, which is harmful to the motor.

Typical problems with the audio device in Xiaomi and their causes

Sound problems in Xiaomi phones can be divided into three categories: hardware, software and external factors.

One of the most insidious things is the problem of "smooth attenuation," like when you listen to music, the volume gradually goes down to zero and then comes back, which can be caused by:

• 🔋 Battery Savings — MIUI automatically lowers volume when charged low.
• 🔊 Overheating - the protection of the audio codec is activated.
• 📱 An app crash (e.g. YouTube Music or Spotify).

💡

If the sound is only lost in a particular application (e.g., TikTok), try clearing its cache in Settings → Apps → [Title] → Memory → Clear the cache.

How to diagnose a faulty audio device

Before you bring your phone to the service, you can do your own initial diagnosis.

1. Testing the speakers through ##6484##

2. Checking microphones in the recorder

3. Connecting headphones (wired and Bluetooth)

4.Resetting the sound settings in MIUI

5. Check for system updates-->

Let's start with the speaker test:

1. Enter ##6484## and select Speaker.
2. If there is sound but quiet, the problem is with the settings or amplifier.
3. If there is no sound, it is possible that the speaker or plume is damaged.

To check the microphones:

1. Run the standard Dictaphone app and record a few seconds.
2. If the recording is silent or with noise, the problem is with the microphone or its contacts.
3. Try recording video: if there is sound in the video, but not when calling - a malfunction in the telephone.

If you only have Bluetooth headphones:

• 🔗 Check codec compatibility in Settings → Connected Devices → [Hearphone Name] → Sound settings.
• 🔄 Reconnect the headphones (forget the device and pair again).
• 📱 Update the headphone firmware (if supported).

⚠️ Warning: If the phone is gone after the phone drops, but everything works in the headphones, most likely, the speaker plume has gone away. Don't try to disassemble the phone yourself: in Xiaomi, the plumes are often glued and easily tear.

Software solutions to problems with audio device

In 70% of cases, Xiaomi's audio problems are solved by software, and here's what you can do without disassembling your phone:

• 🔄 Reboot is trivial, but often helps with audio driver failures.
• 🔧 Reset audio settings: Go to Settings → Sound and vibration → Reset audio settings (in some versions MIUI this item is hidden).
• 📲 App cache cleanup: For YouTube, Spotify, and other media applications, clear the cache in Settings → Apps.
• 🔄 Update MIUI: Go to Settings → About Phone → System Update and check firmware relevance.
• 🛠️ Reset to factory settings (extreme): If nothing helps, back up and reset your phone through Settings → Additional → Restore and Reset.

For advanced users, there are a few more tricks:

• 🔊 Absolute volume shutdown (helps with quiet Bluetooth): adb shell settings put global volume_abs_music 100 (Developer Mode and connection to ADB is required.)
• 🎵 Manual equalizer setting: In Settings → Sound and Vibration → Xiaomi Sound Effects, try turning off all effects and turning them on again.

💡

If the sound problem has occurred after the MIUI update, try rolling back to the previous version via Settings → About Phone → MIUI Version → Three-point icon → Select the service pack (if available).

Hardware malfunctions: when without service can not do

If the software methods didn't work, it's probably hardware, and here are some signs you should go to the service.

• 🔊 The speaker doesn't make any sounds at all (even in test mode ##6484##).
• 🎤 The microphone doesn't work in any application, including the voice recorder.
• 🔌 The sound is lost when the body is pressed (a sign of poor plume contact).
• 💦 Once moisture hit, the sound became quiet or distorted.
• 🔥 The phone overheats when sound is played (may indicate a short circuit in the audio track).

The cost of repairing audio devices in Xiaomi depends on the model and type of malfunction:

Xiaomi service centers often offer replacing the entire audio module (speaker + microphone + plume) as a single unit, which is cheaper than repairing separately, but not always justified. For example, if only the speaker is broken and the microphone is working, you can save money by replacing only the speaker.

⚠️ Warning: In moisture-protected models (IP53/IP68), re-sealing of audio components may be required after the audio component is replaced. Check with the service or the phone will lose water protection.

FAQ: Frequent questions about Xiaomi audio devices