How to increase the sound in headphones on Xiaomi Mi 9

The Xiaomi Mi 9, released in 2019, is still a popular device thanks to its powerful processor and high-quality display.However, many users are faced with a situation where standard speaker volume or audio output through a 3.5 mm connector (when using an adapter) or Bluetooth headset is not enough. This is especially noticeable in noisy places such as the subway, street or gym, where background noise drowns out favorite tracks or podcasts.

The problem with quiet sound is often not hardware, but software constraints set by the manufacturer to protect users’ hearing and comply with European safety standards. Fortunately, the MIUI operating system on which the Mi 9 runs has deep customization potential. There are several proven ways to get around these limitations and make the most of your device’s audio track without losing quality.

In this article, we will take a look at all the volume-boosting techniques, from basic system settings to using engineering menus and third-party software, learn how to properly configure the equalizer, which apps actually work on modern versions of Android, and how to avoid common errors that can lead to audio distortion or damage to headphone speakers.

Basic sound settings and connection check

Before you go to complex manipulations with system files or engineering menus, you need to exclude the banal reasons for quiet sound. Often users forget to check the individual media volume settings, which may differ from the volume of the call. In the Xiaomi Mi 9, audio stream management is divided, and increasing the volume of the ringtone will not affect the music in the player.

Also worth paying attention to the physical condition of the connectors and the headphones themselves. If you use a wired headset through a USB Type-C to 3.5 mm adapter, make sure it is working properly. Cheap adapters without a built-in DAC (digital-analog converter) can work incorrectly with the Mi 9, giving a quiet and distorted signal. For Bluetooth headphones, distance to the signal source and the presence of interference are critical.

It is recommended to perform the following actions for primary diagnosis:

• 🎧 Check if another Bluetooth device is connected that can intercept the audio stream.
• 🔊 Press the volume buttons and make sure that the slider is raised to the maximum in the Multimedia section".
• 🧹 Clean the speaker grid and connectors of dust that can mechanically obstruct sound.
• 🔄 Reboot your smartphone to reset possible software failures of audio drivers.

⚠️ Note: If after connecting the headphones sound remains monophonic or there is a strong hiss, the problem may be incompatibility of the adapter with the protocols Xiaomi Mi 9.

You should pay special attention to the Dolby Atmos settings, if they are available in your firmware version. This surround sound algorithm can both improve perception and reduce overall volume through software processing. Try switching equalizer modes in standard audio settings, choosing presets Bright or Bass, which often have a more aggressive gain curve.

Use of built-in equalizer and sound effects

The built-in MIUI sound personalization tools provide a flexible enough tool to change the frequency response. The standard equalizer allows you to manually raise the volume level at certain frequencies, which is subjectively perceived as an increase in the overall sound level. To access these settings, you need to go to the Settings menu → Sound and vibration → Sound effects.

Here you'll find a graphical equalizer with multiple sliders. To make the sound louder, it's recommended to lift all sliders upwards, create a flat line above zero, or use preset modes. However, beware: over-raising all frequencies can lead to digital distortion (clipping), especially on high-dynamic tracks. A smartphone audiotrack has a physical power limit, and software amplification beyond normal just cuts off wave peaks.

In addition to the equalizer, this section often features the "Mi Sound Enhancer" feature, which optimizes the sound for a particular headphone model. If you have your headphones on the list (for example, MI In-Ear Headphones or popular brands like Sony and Sennheiser), be sure to choose them. The system automatically adjusts the frequency response, which can add missing volume in the medium frequencies where the vocals are located.

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Try activating "In your pocket" mode in the audio settings if available. Sometimes the system mistakenly thinks the phone is in the bag and mutes the sound, thinking that the speaker is closed.

For a more subtle setting, you can use the following recommendations:

• 🎚️ Lift the low-frequency sliders (left) to add power to the basses, which will create the illusion of volume.
• 🎼 Avoid raising the high frequencies (right) above 3-4 dB, so that there is no unpleasant whistle.
• 🎧 Test the settings on different tracks as music genres require a different approach to equalization.

It’s important to understand that the built-in equalizer works at the system level and affects all applications that reproduce sound, making it a versatile tool that does not require additional software installation.

Engineering menu and hidden audio settings

One of the most effective ways to increase volume is to use the Android engineering menu.This is a hidden part of the system designed to test equipment by engineers in the factory. In the Xiaomi Mi 9, access to it can be limited in global versions of the firmware, but often runs through a special set of commands or enhancer applications.

The code #3646633## is traditionally used to enter the engineering menu, typed in the Phone app. However, newer versions of MIUI often block this code. If the code doesn't work, you can use the Engineering Mode app from Google Play, which emulates this call. From the menu you open, you need to go to the Hardware Testing → Audio → Audio Debug tab.

If you find a setting that plays media (often referred to as MUSIC or Media Playback), you can try to increase the value (Gain). The standard value is usually about 120-130. Incremental increase to 140-150 can give a noticeable increase in volume.

⚠️ Warning: Changing the parameters in the engineering menu is at your own risk. Recording current values before changing is mandatory! Excessive increase (Gain) can lead to wheezing, distortion and even burnout of the speaker coil in the headphones.

After making changes, make sure to press the Set or Apply button, and then restart the device. Check the result. If the sound is too distorted, return the values to the original values. Remember that the goal is clear and loud sound, not maximum numbers at all costs.

Third-party sound amplifiers

If built-in tools are not enough, specialized applications from the Google Play Store come to the rescue, they work as an intermediary between the sound source and the output, applying their own amplification algorithms. For the Xiaomi Mi 9 with its powerful Snapdragon 855 processor, such applications work stably and without delay.

One of the most popular and effective solutions is the Precise Volume or Volume Booster GOODEV application. These programs allow you to increase the volume above the standard maximum of the system (up to 1000% in theory, but in practice it is better not to exceed 20-30%).

Another powerful tool is Poweramp Equalizer, which is not just an amplifier, but a full-fledged Pre-amp parametric equalizer, and by setting the Pre-amp to a plus, you raise the overall signal level before you process it with frequency filters, which often yields a cleaner result than simple boosters.

Criteria for choosing a quality amplifier:

• 📱 Compatibility with Android 10/11 (Relevant to the updated Mi 9).
• ⚙️ Ability to fine-tune the limiter to prevent wheezing.
• 🛡️ Lack of intrusive advertising that can overlap the interface.
• 🎚️ Support for separate volume settings for different applications.

It is worth considering that the use of third-party amplifiers increases battery consumption, as the processor is forced to process the audio stream more actively, and some applications require permission to "Change system settings", which you need to grant manually after installation.

Set up Bluetooth codecs for wireless headphones

For wireless headsets owners, the Xiaomi Mi 9 offers enhanced features through the developer menu. Bluetooth audio quality and volume depend on the codec used. By default, the system can choose a low-bitrate codec (such as SBC), which sounds quieter and worse than aptX or LDAC.

To access the codec settings, you need to activate the developer mode. → About the phone and seven times quickly click on the build number (MIUI After the message "You became a developer" appears, go back to the main settings menu, select Advanced Settings. → For developers.

In the list that opens, look for the Audio section.

1. Bluetooth Audio Codec: Select aptX, aptX HD or LDAC if your headphones support these formats.They transfer more data and often have a higher volume level.
2. Bluetooth Absolute Volume: Try to switch this setting. In one position, the volume is controlled jointly by the phone and headphones, in another - independently. Turning off absolute volume sometimes allows you to twist the level on the headphones themselves higher than the phone allows.

Path to settings:


Settings → For developers → Network → Turn off the absolute volume of Bluetooth

Changing the codec may require reconnecting the headphones, and it’s also worth noting that high-resolution codecs (LDACs) consume more power and may be less stable in places with more interference.

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Choosing the right Bluetooth codec (aptX/LDAC) can increase perceived volume and detail without using third-party amplifiers.

Frequent Questions and Challenges (FAQ)