Full Call Configuration on Xiaomi Redmi 4X: From basic parameters to hidden chips MIUI

Xiaomi Redmi 4X It is still a popular budget smartphone due to reliable “stuffing” and support MIUI. However, many users face problems when setting up phone calls: the sound is lost, then the second one. SIM If you don't catch the network, then the contacts don't sync. In this article, we'll look at all aspects of the call configuration, from the basic settings to solving the non-obvious bugs that are specific to this particular model.

Feature of Redmi 4X (codename santoni - support for two SIM-The card (hybrid slot) and specific implementation of Qualcomm Snapdragon 435 communication module, which imposes restrictions on VoLTE, sound quality and switching between operators, we will not only show where standard options are enabled, but also reveal hidden settings. MIUI, Which Xiaomi does not advertise in official documentation.

The article is relevant for all versions MIUI (including MIUI 14), but taking into account the features of the firmware for Redmi 4X. If your phone runs on custom firmware (like LineageOS), some of the instructions may be different – check out the details in the comments.

Basic Call Settings: What Can Be Changed Without Root Rights

To start with, the obvious is the standard call settings menu, and most users are limited to those settings, but even here, there are nuances to be aware of.

To open the basic settings, go to: Settings → SIM-maps and mobile networks → Call settings.

Options are available here:

• 📞 Answering a call - choosing the way to accept the call (swipe up/down, volume button). 4X It is better to leave the swipe up: volume buttons often go off accidentally in your pocket.
• 🔊 Call volume -- adjust separately for calls, notifications and alarms, and this model has the potential to distort the sound at maximum volume -- optimal value. 70-80%.
• 📵 Do Not Disturb Mode is a flexible setting of exceptions for important contacts, useful if you use your phone as a workspace.
• 🔄 Call forwarding – redirecting to another number when busy or unanswered. Works unstable on some operators (e.g. Tele2).

Pay attention to the item Additional settings - here are hidden useful chips:

• 📱 Quick answers - templates SMS If you reject a call, you can edit or add your own.
• 🔇 The vibration in response -- it's separate from the general vibration. It's useful in noisy places.
• 🎧 Notification of the call in the headphones – the sound signal will be played through the Bluetooth headset.

2. Setup of two SIM-Maps: How to avoid network problems

Redmi 4X Supports two nano-SIMs or one nano-SIM + MicroSD: The main problem is that there's a conflict between networks and two operators at the same time:

Go to: Settings → SIM-maps and mobile networks → Management SIM-map.

Here you can:

• 📶 Choose. SIM default, SMS And the mobile Internet. SIM Not catching the network, try to change the priority.
• 🔄 Enable data switching - automatic transition to the second SIM It's not stable on the firmware below. MIUI 12.
• 📞 Set up names SIM — For example, “worker” and “personal” so as not to get confused when calling.

Frequently Mistake: Users forget that Redmi 4X does not support simultaneous work 4G both SIM. If one card is working in the LTE, The second automatically moves into 2G/3G. To fix it:

1. Open the Settings. → SIM-maps and mobile networks → Type of network.
2. For the second. SIM Select Only. 3G (if the operator supports).
3. Reboot the phone.

Make sure that both cards are activated by the operator|

Check the balance on both SIM|

Select priority SIM call-in|

Turn off automatic data switching (if not necessary)|

Reboot your phone after the changes-->

If one of them SIM stopped defining:

⚠️ Attention: On Redmi 4X frequently-false APN post-refresh MIUI. To restore the connection, go to Settings. → SIM-maps and mobile networks → Access points (APN) And you can manually select your operator profile, and if it's not on the list, ask the operator for settings. SMS (usually a command *99# or *100#).

3.Sound problems during calls: diagnostics and solutions

One of the most common complaints about Redmi 4X — Bad sound when talking: the interlocutor does not hear, echo, crackle or no sound at all.

First, check the basic settings:

1. During the call, tap the speaker icon in the call interface to switch between hands-free and handset.
2. Make sure that the In-pocket mode is not activated (turns off in Settings). → Lock screen → Pocket mode).
3. Check if the cover or protective film is drowning out the sound (especially if it covers the upper speaker).

If the sound is completely lost:

For a deep diagnosis:

1. Dial ##4636## (test menu).
2. Select Phone Information.
3. Scroll down to the Audio block and check the status of the microphones (Microphone).If the Microphone 1 or Microphone 2 is 0, the microphone is faulty.

4. VoLTE and HD-Calls: How to turn it on and why it doesn’t work

Redmi 4X Supports VoLTE technology (voice via voice) 4G), But with reservations. First, it has to be activated by your operator. Second, some firmware has this feature hidden.

To enable VoLTE:

1. Go to Settings. → SIM-maps and mobile networks.
2. Choose the right one. SIM-map.
3. Activate the VoLTE call switch (if not, see the instructions below).
4. Reboot the phone.

If there is no VoLTE call:

• 📱 Install the latest version MIUI through settings → The phone. → Updating the system.
• 🔧 Turn on Developer Mode (7 times click on Version) MIUI In About Phone, then in Settings → Additionally. → For developers, activate VoLTE.
• 📲 Check if your operator supports VoLTE (MTS, Beeline and MegaFon have lists of supported regions).

If VoLTE is on, but calls still go through 3G:

⚠️ Attention: On Redmi 4X firmware MIUI 11 may trigger a bug when the phone "forgets" VoLTE settings after rebooting.Solution: disable automatic network switching to Settings → SIM-map → Switch data and manually select Only 4G for SIM-map.

💡

If after turning on VoLTE mobile Internet disappeared, try to disable the function Improved call quality in the settings SIM-Sometimes it conflicts with the settings. APN.

5. Contacts and calls: sync, blacklist and quick dial

Contact issues at Redmi 4X It's often associated with incorrect synchronization or duplication of records, and let's figure out how to set things up correctly.

Synchronization of contacts:

• 📱 By default, the contacts are saved to SIM-To avoid losses, export them to Google Contacts:
• Open the Contacts → Contact Management → Import / Export.
• Select Export to your device (create a.vcf file), then import it to Google.

Blacklist and spam filtering:

• 🚫 To add a number to the blacklist: Open the phone → Journal → press the number → Lock down.
• 📵 To filter spam calls, enable Spam Definition in the Phone app settings.
• ⚠️ On the Redmi. 4X The blacklist is reset after resetting. To save it, export the list of blocked numbers through Settings. → Annexes → Phone. → Warehouse.

Quick dial and gestures:

• ➕ Add frequently used contacts to the home screen: long desktop tap → Widgets → Contacts.
• 📞 Enable Quick Dial in the Phone App: Settings → Quick set. → assign numbers (1-9) touch-up.
• 👆 On the Redmi. 4X It uses a gesture called Double-click on the lock screen to quickly access the camera or flashlight, and to reassign it to the call, use the Button Mapper app (root required).

💡

Synchronizing your contacts with Google is the only reliable way to save them when you reset your phone or replace them. SIM-Local storage on the device or SIM-The map often leads to data loss.

6. Hidden functions MIUI For the call: what is silent Xiaomi

MIUI It contains undocumented features that can be activated through an engineering menu or third-party apps. 4X.

The function "Mode on the plane with calls":

• Allows you to leave your calls on and SMS activated.
• To enable: Activate Flight Mode, then in the notification curtain click on Settings → Additionally. → Turn on the calls and SMS.

Hidden menu of call sound:

• Dial ##36446337## (EMM).
• Choose Audio. → Normal Mode → Sph (microphone) or Sph2 (noise-canceling).
• Here you can manually calibrate the sensitivity of the microphones (it is useful if the interlocutor does not hear you).

Forced Enabling of VoLTE (if the option is hidden):

• Install the app MTK Engineering Mode: Qualcomm Service Menu is suitable for Snapdragon 435).
• Go to BandMode and select LTE ALL for yours SIM-map.
• Save the settings and restart the phone.

⚠️ Warning: Changing the settings in the engineering menu can cause network loss or unstable operation of the communication module. Before experimenting, write down the current settings (take a screen picture) or back up through Settings. → Additionally. → Backup and reset.

7. Solving common challenges

Collected typical complaints of users of Redmi 4X and ways of eliminating them.

If the phone stopped ringing after the update MIUI:

1. Check if the settings have gone wrong. APN (see section 2).
2. Remove the update to the Phone app via Settings → Annexes → Phone. → Remove updates.
3. Reset network settings: Settings → SIM-map → Resetting network settings.

To diagnose hardware problems:

• Call another phone and see if it can hear you.
• Connect headphones – if there is sound in them, the problem is in the speaker or microphone.
• Try another one. SIM-card (preferably another operator).

FAQ: Frequent questions about setting up calls on Redmi 4X