Customize different tunes on the SIM in Xiaomi Redmi 9C NFC

Modern smartphones like the Xiaomi Redmi 9C NFC are often used in dual SIM mode, allowing you to separate work and personal contacts. However, standard audio settings offer a single call melody for all incoming ones, which creates confusion. You can't immediately determine who is calling until you look at the screen, and in your pocket or bag you can't do that.

Fortunately, MIUI provides flexible personalization tools to assign a unique audio track to each SIM card, not just a matter of aesthetics, but also the convenience of using the device in everyday life. In this guide, we will detail how to set up customized ringtones, what file formats are supported, and how to avoid typical synchronization errors.

The process of setting up on Redmi 9C may seem obscure due to the features of the MIUI interface, which hides some advanced options. We will go all the way from preparing an audio file to the final check of the system. It is important to understand that the function requires compliance with certain format conditions and the location of files in the device memory.

Preparation of audio files and format verification

Before you start changing system settings, you need to make sure you have the right files. Not every audio file can be used as a system ringtone. Android, the operating system on which MIUI runs, has strict codec and container requirements to ensure that the call runs smoothly even when the battery is low.

The optimal and most compatible format is MP3. It is supported by all firmware versions without the need for conversion. M4R (Apple standard but often read Android) and OGG can also work. However, using rare codecs like FLAC or high-resolution WAV can lead to the system simply ignoring the file or playing a standard squeak instead of your tune.

Pay attention to the length and size of the track. Too long tracks may be incorrectly cropped by the system or cause a delay in the start of playback. It is recommended to use excerpts lasting from 15 to 30 seconds. Files should be stored in the available memory of the phone, not on remote cloud storage, to provide instant access when an incoming call.

⚠️ Note: Do not use files with DRM-protection (downloaded from paid subscriptions of streaming services without offline access to ringtones) The system will not be able to read the protected content, and the call will pass without sound.

For easy management, it is best to move the desired compositions to a separate folder in advance, which will speed up the search in the system menu for file selection, if your files are in the Downloads folder, they will be more difficult to find among the system garbage and temporary application files.

Standard method of setting up through the contact menu

The easiest way to set different tunes is to use the built-in SIM-linked contact settings menu, which works if the caller is stored in your phone book, and the action algorithm requires care, as the interface may vary depending on the Android version and the MIUI layer.

To start, open the Contacts or Phone app and go to the record you want. Click on the contact name to open the detailed card. Here you need to find the edit button or the specific number settings if the contact has multiple numbers, and that's where the SIM card and the melody are tied.

• 📱 Open the Contacts app and select the right subscriber from the list.
• 🎵 Click on “Melody” or “Rington” in the contact card.
• 💾 Choose the source of sound: internal memory or voice recorder.
• ✅ Confirm the selection, the system will automatically apply the track for calls from this number.

But this method has a major drawback: it only works for saved numbers, and if you get a call from an unknown number to a second SIM card, you'll hear a standard horn, and you'll need to use deeper system settings to prioritize your SIM card.

Configure through the system application "Themes"

In Xiaomi’s ecosystem, the Themes app is not only a wallpaper changer, but also a central hub for managing sound design, and it’s here that the ability to globally customize ringtones for each SIM card separately, whether or not you keep contact, is the most reliable standard method.

Run the Themes app. In the bottom menu or in the profile (human icon), look for the Sound or Ringtones section. Here you will see a list of preset tunes. To add yours, click on the plus or Download button. The system will suggest selecting a file from the device's memory.

The key is to choose the target SIM card. After selecting the file, the system will ask which SIM card to set this ringtone for. You will be prompted to choose SIM 1 or SIM 2. If you do not see this choice right away, it is possible that in your version of MIUI this feature is transferred to the call settings available through the same menu.

It is important to note that the Themes app requires an internet connection to initially sync the directory, but installing local files works offline. If your file list is empty, check the application's memory access permissions in the privacy settings.

Use of third-party call managers

The Xiaomi Redmi 9C NFC’s regular hardware may be limited in some firmware versions, especially global ones, where functionality is cut in favor of Google’s policies, with specialized apps from the Google Play Store taking over incoming call management.

One of the most popular solutions is the SIM Card Ringtone app, which allows you to assign unique tunes not only for each SIM card, but also for groups of contacts or even for incoming / outgoing calls separately, the principle of which is to intercept the call event and play the track chosen by the user instead of the system.

Installing this software requires advanced permissions, you'll need to give access to your phone, contacts, and critically, allow the display over other windows, without which the app won't be able to run the audio player when the call comes in, when the screen is still locked.

⚠️ Warning: When using third-party call managers, make sure that the battery settings for this application are power-saving. Otherwise, the system will “kill” the application process in the background, and the call will pass without sound or with a delay.

The advantage of third-party solutions is flexibility. You can customize different sounds for missed, busy lines, and even video calls, but it's worth remembering that this is an additional expense of CPU and RAM, which on a budget device like the Redmi 9C can be noticeable.

Creating personalized sound profiles

For advanced users who want to achieve perfect control, there is the possibility of creating sound profiles. Although the pure profiles of Work, Home, Meeting in MIUI are poorly implemented, they can be emulated through automation or manual switching of audio settings.

The idea is to pre-prepare sets of tunes, for example, for a working SIM card, you download strict, short signals, and for a personal one, you download longer, more melodic compositions, and then you back up those settings or you just remember the configuration.

Some users use automation scenarios (via Xiaomi’s Auto Tasks app) to change the ringtone depending on the time of day or geolocation, such as a silent vibration signal on a second SIM card at night and a loud melody during the day.

It takes discipline, but it's a great way to get the results, because you can instantly understand the nature of the call without even pulling the phone out of your pocket, and this is especially true in noisy places where visual screen control is difficult.

Troubleshooting and troubleshooting

Even with accurate follow-up to instructions, Xiaomi Redmi 9C NFC users may encounter problems, most often related to system cache or MIUI version conflicts. If the melody does not play or resets to a standard one after installation, try clearing the cache of the Themes and Contacts app.

Another common problem is that the file is too high quality or bitrate, the system may not have time to decode a heavy MP3 file at the time of the call. Try converting the track to a lighter format with a bitrate of 128 kbit / s. This will not significantly affect the auditory perception of the short fragment, but will increase compatibility.

Also check if Do Not Disturb or Quiet Mode is enabled for a particular SIM card. In modern versions of MIUI, you can set the silence schedule separately for each line. Make sure that these modes are not active at the time of the test.

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Tip: If the melody breaks in the middle of a word, try adding 2-3 seconds of silence to the end of the file before cropping. This will prevent the system from abruptly breaking the sound.

In rare cases, a complete reset to the factory audio settings through the engineering menu helps, but this action requires caution. Usually, it is enough to simply restart the device after installing new ringtones to make the changes take effect correctly.

The Impact of MIUI on Sound Functionality

Note that the interface and available options are highly dependent on the version of the firmware installed. Redmi 9C owners may have MIUI 11, 12 or more new versions, and in each of them the path to settings may differ. Global ROMs often have a reduced functionality compared to Chinese ones (CN ROM).

With newer versions of the shell, Xiaomi is actively integrating with Google services, which changes the logic of calls. Google’s standard phone set can block access to deep ringtone settings, redirecting the user to a simplified menu, in which case using third-party launchers or call managers becomes the only way out.

Keep an eye out for system updates. Sometimes sound bugs are patched with security patches. If you have any different tunes stopped working after the update, it makes sense to search forums for specific bugs in your firmware version.

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The success of customizing different tunes depends on a combination of three factors: the correct file format, the use of the Themes system application, and the correct resolutions for SIM cards.