Modern smartphones have long since ceased to be just devices for calls, becoming powerful multimedia centers, and the Xiaomi Redmi Note 9 model is no exception. The ability to broadcast a screen image to a large monitor or TV opens up new horizons for watching videos, games and presentations without having to buy additional cables. The technology, known as a wireless display, allows you to mirror the content of your gadget on an external receiver using standard Wi-Fi Direct and Miracast protocols.
Redmi Note 9 owners often face the need to quickly show photos to relatives or run a film at home theater without getting confused in the wires. The built-in MIUI feature makes this process as simple as possible, although it has its own nuances depending on the firmware version and the model of the receiving device. Understanding the principles of this module will help you avoid common errors when connecting and enjoy a quality picture.
This article will take a look at the technical aspects of wireless screen operation, step-by-step activation instructions and typical problem solving techniques. We will look at why sound can be lost, how to reduce latency in games, and what alternative applications can be useful if the standard method does not work.
Technological Basis of Image Translation
The feature that users often search for as a “wireless display” is based on the Miracast standard developed by the Wi-Fi Alliance. Unlike Chromecast, which requires installing the Google Home app and works on the “casting” principle, Miracast creates a direct peer-to-peer connection between the smartphone and the TV. This means that the Xiaomi Redmi Note 9 acts as a signal source, encoding the video stream and transmitting it directly to the receiver, bypassing the router if DLNA mode is not used.
It is important to understand that the quality of data transfer directly depends on the supported codecs and the frequency of the wireless module. the Redmi Note 9 smartphone is equipped with a Wi-Fi 5 module (802.11ac), operating in the 2.4 GHz and 5 GHz bands. Using the 5 GHz band is critical for high-resolution video transmission, as it provides higher bandwidth and less exposure to interference from household appliances.
⚠️ Note: Using the 2.4 GHz band may cause artifacts, image jerks or sound desynchronization, especially when streaming video to 4K or dynamic scenes in games.
The MIUI shell on the Redmi Note 9 has a deeply integrated driver for processing video streams. When you activate the broadcast function, the device's processor begins encoding the image in real time, which puts additional strain on the CPU and GPU. That's why during live broadcasts the device can heat up more than usual, and the speed of the interface can decrease slightly.
Technical details of codecs
Search and activate functions in MIUI
The MIUI shell interface may vary depending on the Android version and regional firmware (Global, EEA, China), which often confuses users. In most current versions, the feature is hidden in the control panel, but its widget can be removed by default. To find the tool, you need to unlock the screen and swipe down to open the control panel where the Wi-Fi and Bluetooth switches are located.
If the Translation or Wireless Monitor icons are not visible, click the edit button (usually a pencil or gear icon in the corner of the panel) and find the appropriate element and drag it to the active zone, then access the function in a single touch, which greatly simplifies interaction with external displays.
The alternative is through system settings. You need to go to Settings → Connection and Sharing → Broadcast. In some versions of the firmware, this item may be called "Wireless Monitor" or located in the "Connected Devices" section. Clicking this section starts scanning the surrounding space for available receivers.
💡
If you use the broadcast frequently, add the Translation widget to your desktop via the widget menu (long tap on the blank spot of the screen) so you don’t search for it in the panel every time.
It's worth noting that the feature doesn't require an internet connection to work, but the Wi-Fi module must be enabled. The smartphone uses Wi-Fi Direct to set handshake protocol with the TV. If your device is on flight mode, the function won't work because the radio module is software-enabled.
Step-by-step instructions for connecting to the TV
The process of pairing the Xiaomi Redmi Note 9 with the TV requires a certain sequence of actions. First, you need to make sure that the TV supports Miracast technology (often called Screen Mirroring, Smart View, Share, etc. in the TV menu) and is in standby mode. Once you activate the search on the TV, you can start setting up the smartphone.
☑️ Connection algorithm
Once you have selected your TV on the list on your smartphone screen, the handshake process will begin. The TV screen may have a request for confirmation of connection, which must be accepted by the remote control. Successful connection will be marked by the appearance of a copy of the smartphone screen on a large display. The image may not appear immediately, but after 5-10 seconds, which is a normal buffering delay.
It's important to consider the orientation of the screen. If you hold the phone upright, the image on the TV will have black stripes on the sides, if the TV can't automatically turn the picture. To watch the video, you'd better turn the smartphone into horizontal mode to use full-screen mode and hide the Android system panels.
| Parameter | Meaning/Description | Impact on quality |
|---|---|---|
| Permission | Up to 1080p (Full HD) | High, clearly readable text |
| Frequency of personnel | 30-60 FPS | Smoothness of cursor movement and video |
| Delay (Latency) | 100-300 ms. | Critical for dynamic games |
| Audio codec | AAC / SBC | Quality of the transmitted sound |
If the connection is successful, the smartphone notification panel will display an active connection icon, clicking on it, you can quickly break the connection or change some display settings, and the option to turn off the smartphone screen during active broadcast is often available in this menu, which saves battery power.
Customization of quality and elimination of delays
One of the main problems with wireless broadcasting is latency. This is not critical for watching movies, but in games or when using a smartphone as a presentation console, lagas can be annoying. To minimize latency on the Redmi Note 9, it is recommended to turn off background downloads and close heavy applications that consume CPU resources.
The key factor is the distance between devices. Wi-Fi Direct operates within line of sight or through a single wall. If there are many obstacles between the smartphone and the router (or TV if it is connected over Wi-Fi), the signal will degrade. The optimal distance is 2-3 meters, which ensures a stable communication channel without loss of data packets.
In some cases, rebooting the Wi-Fi module helps. It is enough to turn the Reim flight on and off for a couple of seconds to reset the network settings and reconnect to a freer communication channel, and it is also worth checking whether the air is overloaded with neighboring networks, especially if you are in an apartment building.
⚠️ Attention: Use VPN-The transmission of the image can be completely blocked by the virtual tunnel, which changes the traffic route, making it impossible to locally detect the devices.
For users who want maximum performance, there is a hidden setting in the developer menu. By activating the developer mode (click seven times on the build number in Settings → About phone), you can find the item "Enable hardware acceleration of the GPU" or codec settings, but changing these parameters without experience can lead to unstable system operation.
Working with sound during broadcasting
A common problem is the lack of sound when a successful image is transmitted. Miracast protocol supports audio streaming, but sometimes Android defaults to output audio through a smartphone speaker or connected Bluetooth headphones. To fix this, you need to press the speaker icon in the control panel or in the broadcast menu during an active broadcast and select "TV" as the output device.
If the sound wheezes or is interrupted, this indicates a lack of channel bandwidth, in this case, reduce the audio quality in the Bluetooth settings (if the sound is going through it) or simply close the background applications. It is also worth checking the settings of the TV itself: perhaps there is a mode "Cinema" or "Sport", which introduces additional processing of the sound, creating a dissynchron with the picture.
Some video players are also notable for their work: apps like Netflix or Disney+ can block the output of images wirelessly due to the protection of HDCP content. In such cases, a black image with sound working can be displayed on the TV screen, or the connection will be broken immediately after the video is launched.
💡
For legal streaming content with DRM protection, use the built-in “Cast” button inside apps (YouTube, Netflix) rather than the system function of “Translation” of the entire screen.
If the sound is completely absent, try changing the sample rate in the developer settings or restarting the audio service by turning the smartphone off and on completely. Sometimes the problem lies in the incompatibility of audio codecs between the MIUI version and the TV software.
Alternative methods and applications
If the standard Wireless Display feature on the Xiaomi Redmi Note 9 is unstable or the TV does not support Miracast, you can use third-party solutions. One of the most effective methods is using the Google Home app, which allows you to broadcast the screen to Chromecast devices or TVs with built-in Android TV. This method often provides a more stable connection and better picture quality.
For Samsung TVs, there is a separate SmartThings app, and for LG, LG ThinQ. These programs use proprietary protocols that can be optimized better than the universal Miracast. Installing such an app on the Redmi Note 9 could solve compatibility issues and add additional features, such as using the phone as a touchpad.
Another option is the use of DLNA-servers for transmitting media files, unlike mirroring, DLNA It allows you to send only a specific video file or photo to the TV without loading the smartphone processor with constant encoding of the interface image.