The Xiaomi Mi 9T, also known as the Redmi K20 in the Asian market, has one of the best audio tracks in its class thanks to a dedicated DAC from ESS Technology. However, standard settings are often not enough to unlock the potential of built-in speakers or connected headphones. Users often wonder how to activate hidden or advanced signal processing functions to get a cleaner and deeper sound.
In this article, we will discuss in detail how to enable sound optimization on the Xiaomi Mi 9T, using both the standard MIUI shell tools and additional engineering settings. You will learn where the professional equalizer hides, how to set up the Mi Sound Enhancer correctly and what options should be changed to achieve the perfect frequency balance.
It's worth noting that the quality of playback depends not only on the software, but also on the right file format and type of headset used. Xiaomi's built-in algorithms can work wonders if you know where to click. The key here is activating Hi-Fi mode and calibrating the frequencies correctly for a particular headphone model. Let's get to the practical part of the setup.
Basic setup of sound effects in MIUI
The first step to improving audio experience on your device is to activate standard but powerful shell tools. Android, in conjunction with MIUI, offers a wide range of features that are often overlooked by beginners. First, you need to get into the audio settings menu, where the main controls are located.
Go to Settings → Sound and Vibration → Sound Effects. This is where the Mi Sound Enhancer switch, which is the heart of the smartphone audio system, is turned on, and when it's turned on, the processor starts to process the signal more aggressively, highlighting low frequencies and making high frequencies more ringing. But just turn it on a little bit, you need to adjust the profile.
Inside the effects menu, you'll find a choice of headphone type, which is a critical parameter, because optimization algorithms are built on the characteristics of the hardware you're connected to. If you're using built-in speakers, select the appropriate item so that the system applies a profile that extends the stereobase.
- 🎧 Headphones-in-ears: profile, enhancing the average frequencies for better legibility of vocals.
- 🎧 Headphones-drops: a mode that adds bass and volume sound.
- 🔊 External speakers: settings to prevent wheezing at maximum volume.
- 🎼 Portable speakers: profile for connecting via AUX Bluetooth.
Remember that for each type of connection (a 3.5 mm connector or Bluetooth), the settings can be saved separately. After choosing the type of device, be sure to calibrate if the system offers it. It will only take a minute, but the result will pleasantly surprise you.
Activation of Hi-Fi mode and work with DAC
The main feature of the Mi 9T is the presence of a dedicated digital-to-analog converter ESS ES9218P. This is not just a marketing trick, but a real hardware module that takes over the sound processing, unloading the main processor and significantly reducing noise. To use this powerful resource, you need to turn on Hi-Fi mode.
To activate, look for a Hi-Fi switch in the audio effects menu. When you turn it on, you will notice that the volume level may change, and the status bar will appear the corresponding icon. In this mode, some software restrictions and effects are turned off, so that the signal passes through the DAC in the purest possible form.
⚠️ Note: In Hi-Fi mode, some third-party applications may not control volume correctly. If you encounter silence in a particular player, try temporarily turning off Hi-Fi or changing the settings of a particular application.
Hi-Fi is especially recommended for listening to Lossless formats (FLAC, WAV) and using a high-quality wired headset. With wireless headphones, the difference may be less noticeable due to the limitations of the Bluetooth codec, but the detail will still improve.
There is also a hidden engineering mode for deeper DAC customization, which is sometimes accessed through special applications or codes, but the standard menu is usually enough for 95% of users.
☑️ Checking Hi-Fi settings
Fine equalizer tuning for different genres
The regular equalizer in the Xiaomi Mi 9T has a wide range of adjustments. Standard presets like Rock, Pop or Jazz are just the base. The magic begins when you move to manually adjusting the frequency sliders. Understanding what each band is responsible for will allow you to create the perfect sound signature.
Low frequencies (60Hz - 250Hz) are responsible for the bass and body of sound. Raising them will add power, but excess will make the sound buzzing and unintelligible. Mid frequencies (500Hz - 2kHz) are the area of vocals and most instruments. Their neat lifting will make the music more "live" and present.
| Frequency (Hz) | Impact on sound | Recommendation |
|---|---|---|
| 60 - 150 | Deep bass, foundation. | Raise for electronics and hip-hop |
| 200 - 500 | Warmth, humour | Slightly lower if the sound is "mushy." |
| 1k - 4k | Vocals, instrument attack | Add for clarity (clarity) |
| 8k - 16k | Air, details, hissing | Raise for classics and jazz |
When manually adjusting, try not to make sharp jumps. The smooth lines of the equalizer graph usually give a more natural sound than sharp peaks and dips. Save your preset under a unique name to easily switch between customized profiles.
The secret technique of equalizer tuning
Use of Dolby Atmos and Third Party Codecs
Thought Xiaomi Mi 9T It does not have official Dolby Atmos certification in global firmware, and many users successfully install modified audio drivers or use third-party applications to emulate spatial sound. APK-Files from unverified sources can be improved by Bluetooth settings.
In Settings → Bluetooth, find the connected device and click on the gear next to it. Here you can select the data codec. For the Mi 9T, aptX, aptX HD and LDAC are available (if the Android version and firmware allow). The choice of high-bitrate codec is critical for wireless sound.
- 📡 SBC: Basic codec, low quality, high compatibility.
- 🎵 AptX: Good quality, close to CD, low-key.
- 💎 aptX HD: High resolution, detailed sound.
- 🚀 LDAC: maximum Bluetooth transmission quality (up to 990 kbit / s).
If your smartphone doesn’t offer a choice of codecs in the standard menu, you can use the developer menu. To activate it, click 7 times on the MIUI version in the About Phone section. Then, in the advanced settings, find the Bluetooth Audio Codec and force the desired format.
⚠️ Note: Use of high resolution codecs (LDAC, aptX HD) can discharge the battery of a smartphone and headphones faster, and also cause interruptions of sound when a bad signal is.
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Choosing the right Bluetooth codec can improve wireless audio quality by 40-50%, making it comparable to a wired connection.
Hidden opportunities through the engineering menu
For advanced users who are not afraid to get inside the system, there is access to an advanced audio menu that allows you to adjust the sensitivity of the microphone, the level of amplification of the speakers and other parameters hidden from the average user.
Try entering ##6484## to log into the engineering test menu, where you can select Audio and run speaker and microphone tests. Deeper setups are often available through apps like Volume Control or similar Google Play utilities that require root rights or ADB permissions.
Be extremely careful when changing the gain values. Too high a level can lead to overloading of speakers and their physical damage ("wheezing" or rupture of the membrane), it is recommended to make changes in steps of no more than 2-3 units and immediately check the result.
adb shell am start -n com.android.settings/.Settings$SoundSettingsActivityThis ADB command opens an extended audio menu if the standard input is blocked by the manufacturer, however, for most users, the features described in the previous sections are sufficient to get an excellent result without the risk of "bricking" the audio track.
Optimizing Sound for Multimedia and Games
The scenarios for using the smartphone are diverse: someone listens to symphonic music, and someone plays shooters, where the sound of footsteps is important. For games in Mi 9T, there is a separate option - Game Turbo. In this mode, you can adjust the sound balance, shifting the emphasis to high frequencies to better hear shots and recharge.
When watching movies, it's important that the dialogues are legible and the explosions don't overlap speech, so you can use the equalizer mode of "Cinema" or the manual settings we talked about above, and you can also look at the Mi Video feature, which has its own built-in audio amplifier that works regardless of the system settings.
Remember to clear the cache of audio services if you notice a desynchronization of sound and video or periodic wheezing. → All applications → Settings → Warehouse → Clean (for system sound processes).
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For maximum immersion in games, use wired headphones with closed acoustics and turn on the Game mode in the equalizer to enhance the frequency range where the sound effects of steps and shots are located.