How to increase the volume in headphones on Xiaomi Redmi 9T: from standard settings to hidden features

Xiaomi Redmi 9T is a popular smartphone with good sound, but sometimes owners face a problem: headphones play too quiet, even at maximum volume. The reasons can vary from the limitations of MIUI firmware to the hardware features of the model. In this article, we will discuss all the ways to increase the sound in headphones, including hidden settings and safe workarounds.

It's important to understand that quiet sound doesn't always mean a break. It's often the result of software constraints that can be avoided without harming the device. We tested all the methods on the Redmi 9T with the latest MIUI 12/13/14 versions, and most of the solutions work on other Redmi Note and POCO models.

Before you start settings, check the basics: connect the headphones to another device (to prevent them from malfunctioning), clean the 3.5mm connector of dust and make sure that the headphones do not have a physical volume control. If the problem persists, go to the instructions below.

1. Standard volume settings in MIUI

Start by checking the obvious parameters. MIUI has separate media, call and alarm controls, and hidden headphone options.

Open Settings → Sound and vibration. Here you will see a few sliders:

• 🔊 Multimedia Volume is the main regulator for music and video.
• 📞 Call volume – does not affect the headphones, but sometimes knocks down the general settings.
• 🛎️ The volume of the alarm clock is a separate channel not associated with headphones.

Drag the media slider to maximum and test the sound.

If the volume is still low, try to turn on the headphone amplification (not available on all firmware).

1. Go to Settings → Special features → Improve the sound.
2. Activate the option to amplify the sound in the headphones (if any).
3. Choose a Music or Multimedia profile.

⚠️ Note: On some versions MIUI 14 this option may not be available. If it's not available, move on to the next one.

2. Engineering menu: hidden sound settings

The Redmi 9T has a hidden engineering menu where you can fine-tune sound settings, including volume limits, which requires caution but gives you a noticeable increase in volume.

To open the engineering menu:

1. Launch the Phone app.
2. Enter the combination: ##36446337## (code may not work on some firmware).
3. If the code doesn’t work, try ##4636##, then go to the Hardware testing → Audio tab.

From the Audio menu, select Headset Mode and change the values:

• 🔧 Max Vol - Maximum volume (increase to 150 or 160).
• 🔧 Min Vol - Minimum volume (leave by default).
• 🔧 Current Vol - Current Volume (set to maximum).

Warning: Increasing the Max Vol above 150 can cause sound distortion or damage to the headphone speakers! Start at 140 and gradually improve by testing the sound quality.

3. Sound amplification applications

If standard methods didn't work, try third-party utilities. They work at the system level and can bypass the limitations of MIUI. The best options for Redmi 9T are:

To install ViPER4Android, you will need:

1. Get root rights (for example, through Magisk).
2. Install the ViPER4Android FX drivers.
3. In the application settings, enable Master Limiter and increase Pre-Amp to +3...+6 dB.

⚠️ Attention: Inept use ViPER4Android This can overload the sound card and distort the sound. Start with the minimum values of the Pre-Amp (+1...+2 dB) and check the result.

4. Equalizer setting in MIUI

MIUI has a built-in equalizer that can indirectly affect the perceived volume, and the right settings will help you pull out the sound, especially if the headphones are weak bass or high frequencies.

How to set up:

1. Open the Music app (standard MIUI player).
2. During playback, tap on the icon. ⚙️ Settings → equalizer.
3. Choose preset Rock or Pop – they amplify the average frequencies, which subjectively increases the volume.
4. Manually lift the sliders at 60 Hz (bass) and 10 kHz (upper frequencies) at +3... +5 dB.

On Redmi 9T, the built-in equalizer only works in the standard Music app. It doesn't apply on Spotify or YouTube Music - use third-party equalizers from the previous section.

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If the sound gets worse after you set up the equalizer (wheezing, distortion), reset the settings to the factory and try another preset, often the problem is too high bass on cheap headphones.

5. Check the 3.5mm connector and Bluetooth headphones

If the sound is quiet only in wired headphones, the problem may be a 3.5mm connector. On the Redmi 9T, that's a weak spot, the contacts are oxidized or contaminated.

• 🔍 Check the connector for dust, rust, or bent contacts.
• 🧴 Clean the connector with a cotton swab soaked in isopropyl alcohol (do not use water!).
• 🔌 Connect the headphones to the end – sometimes the contact disappears due to an incomplete plug entry.

For Bluetooth headphones, check out:

1. Connection Codec: Go to Settings → Bluetooth → ⚙️ headphone-on → Codec, choose. AAC Or aptX (if supported) The codec gives you worse quality.
2. Signal Level: If the headphones are far from the phone, the sound may "cut" and appear quieter.
3. Developer settings: activate Bluetooth Debugging in Settings → About Phone → MIUI Version (tap 7 times) → Developer settings → Debugging over Bluetooth.

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On the Redmi 9T, the maximum volume via Bluetooth is 10-15% lower than over the wire.This is the hardware limit of the Qualcomm Snapdragon 662 chip.

6. Resetting the sound settings to factory

If all previous methods didn't work, the system settings of the sound may have gone wrong.

1. Go to Settings → System and device → Resetting.
2. Select Resetting Sound Settings (not to be confused with a full phone reset!).
3. Confirm the action and restart the device.

After discharge:

• 🔄 Loudness will return to factory values.
• 🎵 The equalizer and sound effects will be turned off.
• 📱 You will have to reconfigure the notifications and signals.

If that doesn’t work, there are two options:

1. Update MIUI to the latest version (sometimes new firmware fixes sound bugs).
2. Contacting a service center may be a problem in the sound card or connector.

7. Alternative methods: from USB-C to external UHF

If you are critically important volume, consider hardware solutions:

• 🎧 USB-C Headphones (for example, Xiaomi Hybrid) – bypass the built-in amplifier and give a clean sound.
• 🔊 External UHF (amplifier) - connects through USB-C and powered by the phone.
• 📱 adapter USB-C → 3.5mm with its own DAC (e.g. Apple) USB-C to 3.5 mm).

The advantages of USB-C solutions:

• ✅ Bypass the limitations of the built-in sound card.
• ✅ Better sound quality (especially with external DACs).
• ✅ Compatible with future devices (many new smartphones have abandoned the 3.5 mm).

Disadvantages:

• ❌ Additional expenses (from 1 000) ₽ adapter).
• ❌ Charging your phone and listening to music at the same time will not work.

FAQ: Frequent questions about the sound on Redmi 9T