Improve the sound on the Redmi Note 9 Pro: from standard settings to advanced tweaks

Xiaomi Redmi Note 9 Pro is a popular smartphone with decent specs, but the factory sound settings often leave much to be desired. Dim bass, low volume or distortion at high frequencies can spoil the experience of music, video and games. Fortunately, you can improve the sound both with standard MIUI tools and with third-party tools.

In this article, we’ll look at 7 proven methods, from simple changes in settings to installing specialized applications and even hardware improvements, and it’s important to understand that sound quality depends not only on the software part, but also on the hardware limitations of the speakers and the Qualcomm Snapdragon 720G audio chip used in the Redmi Note 9 Pro.

We tested all of the methods described below on the Redmi Note 9 Pro with MIUI 14 (Android 12) – the results vary depending on the firmware version, but the general principles remain relevant. If you are willing to spend 10 to 30 minutes tuning, the sound of your device will change.

1. Optimization of standard sound settings in MIUI

Start with the basics – often users are unaware of the hidden features of MIUI. Go to Settings → Sound and vibration and pay attention to the following points:

• 🔊 Equalizer: Turn it on and select the Bass Preset or Rock for a more saturated sound. If there are no presets, upgrade your firmware or install Mi Sound Enhancer from the Mi App Store.
• 🎵 Dolby Atmos: Activate this mode (if available in your version) MIUI). It mimics surround sound, especially noticeable in headphones.
• 📱 Media volume: Make sure the slider is set to maximum – sometimes system limits lower volume automatically.
• 🔇 Safe Volume: Turn off this option in Additional Sound Settings if it is active – it artificially limits the sound level.

An important nuance: on some firmware, Dolby Atmos only works with headphones, not through speakers. If this item is missing, then your version of MIUI does not support it (relevant to European and global builds), in which case move to the next section.

Also check the settings of individual apps, for example, YouTube or Spotify may have an equalizer that conflicts with the system, disable it or synchronize settings to avoid distortion.

2. Installation of third-party equalizers and sound amplifiers

Standard MIUI instruments are limited, so you'll need third-party applications to make a big sound improvement.

• 🎛️ Wavelet (free, with purchases): Uses ViPER4Android under the hood, supports automatic tuning to your headphones, perfect for bass and high-frequency cleanliness.
• 🔊 Poweramp Equalizer (paid): One of the best equalizers for Android with support for 32-bit sound. Works at the system level, if you give it permission through the use of the system. ADB.
• 🎧 JamesDSP (Free): Powerful audio processor with support LDAC And aptX. Requires Magisk to work properly.

To install Wavelet or JamesDSP without root permissions, follow the following steps:

1. Download the app from Google Play or 4PDA.
2. Turn on Developer Mode: Go to Settings → About Phone → MIUI Version and tap 7 times.
3. Return to Settings → Additional → For developers and activate Debugging over USB.
4. Connect your phone to your PC and execute the command: adb -d shell pm grant com.pittvandewitt.wavelet android.permission.WRITE_SECURE_SETTINGS

The equalizer will then have access to the system audio settings, and JamesDSP will need to install the module via Magisk Manager.

⚠️ Note: When using JamesDSP or ViPER4Android If you have the wrong settings, you may have a distortion of the sound or even damage to the speakers. Start with minimal changes in the equalizer and gradually increase the levels.

3. Sound tuning through the engineering menu (MTK Engineering Mode)

The Redmi Note 9 Pro is built on Qualcomm's platform, but it has a hidden engineering menu that allows you to fine-tune the audio settings.

1. Open the Phone app.
2. Enter the code: ##36446337## (or #4636## for the alternative menu).
3. Go to the Hardware Testing → Audio section.

Here you will see a few tabs:

• 🔈 Normal Mode: Volume adjustment for different scenarios (calls, media, alarm clocks).
• 🎚️ Headset Mode: Headset settings (increase Max Vol to 150-160 for higher volume).
• 🔊 Speaker Mode: In-line speaker settings. Be careful - increasing values above 180-200 can lead to distortions.

Recommended values for bass amplifier:

Warning: Changes to the engineering menu are not reset after rebooting, but may fly off after a firmware update.Write down the original values to return them if necessary.

Hardware improvements: speaker replacement and sound insulation

If the software methods don't work, you should consider the physical improvements. The Redmi Note 9 Pro uses a single bottom speaker (mono), which limits the stereo effect.

• 🔧 Replacement of the speaker: The original speaker has resistance ~8 You can set the analogue with the best characteristics, for example, from the Redmi Note. 10 Pro (article) 1605-00020).
• 🛠️ Soundproofing: Glue the inside of the back cover with a vibrating material (e.g. Dynamat) to reduce resonance and improve the clarity of sound.
• 🔊 Extra speaker: Artisans install a second speaker at the top of the body, connecting it parallel to the main one. Requires rations and knowledge of circuitry.

To replace the speaker will need:

• New dynamics (cost) ~500–1000 ₽).
• A set of T3-T5 screwdrivers and plastic shoulder blades.
• Dryer for softening the glue (temperature ~60 ° C).

Critical: if you don't install the extra speaker correctly, you can have a battery that's zero because of a short circuit. If you're not sure about your skills, you can contact the service center.

⚠️ Warning: Self-disassembly of the Redmi Note 9 Pro will void the warranty (if it is still valid).Before work, back up the data and charge the phone to 50-70%.

5. Sound optimization for specific applications

Different programs use audio engines in different ways, like Spotify having a built-in equalizer, and YouTube can compress sound when stream quality is low, and here's how to customize popular services:

🎵 Spotify

Go to Settings → Play → Equalizer and activate the Bass Booster preset. Also enable High Stream Quality (320 kbps) in Settings → Sound Quality.

🎬 YouTube

Install the Enhancer for YouTube extension (for the browser) or use the YouTube Vanced app (if it still works).

• 🔊 Force VP9 (for better sound in high resolution).
• 🎚️ Audio Boost (increases volume by 20-30%).

🎮 Games (PUBG, Call of Duty)

In games, the sound is often optimized for voice chat rather than effects.

• Turn off the voice chat by default.
• Install. 3D-Audio (if you have such an option).
• Use headphones with virtual surround (such as Razer Kraken).

💡

For games with important sound positioning (such as PUBG Mobile), include the FPS Competitive preset in Wavelet, which emphasizes steps and shots.

6.Use of Bluetooth codecs for wireless headphones

If you listen to music through Bluetooth headphones, the sound quality depends on the codec you use. Redmi Note 9 Pro supports:

• 🎧 SBC (basic, low-quality).
• 🎵 AAC (It’s better for iOS devices, but it works on Android as well).
• 🔊 aptX and aptX HD (High quality but requires compatible headphones).
• 🎚️ LDAC (Maximum quality but high battery consumption).

To force aptX or LDAC to be enabled:

1. Enable the Developer Mode (as described above).
2. Go to Settings → System → For developers.
3. Find Bluetooth Audio Codec and Bluetooth Audio LDAC.
4. Select aptX HD or LDAC (priority: 990 kbit/s).

To check the current codec, install the Bluetooth Codec Checker app. If your headphones don't support aptX or LDAC, AAC is the best option.

⚠️ Attention: Codec LDAC It drains the battery of both your phone and your headphones, and only use it when you're charging.

💡

For maximum audio quality via Bluetooth, use headphones with support for aptX Adaptive or LDAC and force these codecs to be enabled in the developer settings.

7.Alternative firmware and cores for audiophiles

If you're willing to take drastic measures, consider installing custom firmware or a sound-optimized core.

• 📱 LineageOS: Pure Android with Support ViPER4Android system-level.
• 🔧 KernelSU: Modified core with improved audio drivers.
• 🎛️ ArrowOS: Firmware with integrated Dolby Atmos and Dirac Audio.

Installation process:

1. Unlock the bootloader through the Mi Unlock Tool (linking to the Mi Account is mandatory).
2. Install TWRP Recovery or OrangeFox.
3. Sweep through firmware and GApps (if you need Google services).
4. For the kernel, use FrancoKernel or Perseus with support for f2fs.

After installing custom firmware:

• Activate ViPER4Android via Magisk.
• Turn on Dirac Audio in the sound settings.
• Turn off Mi Sound Enhancer (it can conflict).

FAQ: Frequent Sound Improvement Questions on Redmi Note 9 Pro