Modern Xiaomi Redmi and POCO smartphones offer users not only powerful hardware, but also advanced multimedia capabilities. One of the key parameters for music lovers is the quality of wireless audio transmission. When it comes to wireless headphones, owners often hear the term aptX, but not everyone understands what is behind this acronym and how it affects the listening to music in your device.
In essence, aptX is a family of proprietary codecs developed by Qualcomm that allow high-quality audio to be transmitted over a Bluetooth connection with minimal latency and compression. Unlike the standard SBC codec, which is used by default in all Bluetooth devices, aptX technologies provide more detailed sound, preserving frequencies that are usually “cut” when the signal is compressed strongly.
But having support in a smartphone is only half the equation: The technology requires that both the transmitter (your Redmi) and the receiver (earphones or speakers) support the same coding standard. In this article, we’ll go into detail about which versions of aptX are available in the Xiaomi ecosystem, how to check for them and whether to chase the most expensive codecs.
What is AptX and How it Works on Android
The basic principle of any Bluetooth codec is to compress the audio stream for fast transmission over a narrow channel and then recover on the side. The standard SBC codec, mandatory for the Bluetooth specification, uses aggressive compression, which often leads to loss of parts in high frequencies and the appearance of artifacts. aptX technology approaches this process differently, using more complex coding algorithms ADPCM (Adaptive Differential Pulse Code Modulation).
The main advantage is that aptX is able to transmit audio with a bitrate of up to 352 kbit / s (in the version of aptX HD - up to 576 kbit / s), whereas SBC rarely exceeds 320 kbit / s, and in reality often works at 192-256 kbit / s. This allows you to achieve sound quality close to CD (16 bit / 44.1 kHz), which is especially noticeable on high-quality acoustics. In Xiaomi smartphones, the implementation of these codecs is built into the level of Qualcomm Snapdragon chipset drivers.
⚠️ WARNING: Even if your smartphone supports aptX, the sound won’t be “magic” if you use cheap Bluetooth headphones with small speakers.
It’s important to understand the difference between a system’s support for a codec and its active use. Android (and the MIUI or HyperOS shell) automatically selects the best common codec for a pair of devices. If your headphones only support SBC, Xiaomi will switch to it, ignoring the capabilities of aptX. The switching happens unnoticed by the user when paired.
Varieties of codecs in Xiaomi and Redmi smartphones
The Qualcomm ecosystem offers multiple versions of the technology, and support for a particular one depends on the CPU model installed in your Redmi or Xiaomi.Not all smartphones are the same: budget models can have a limited set of codecs, while flagship lines support the full range of available formats.
Below is a table to help you understand the main differences between codec versions that can be found in Xiaomi devices:
| Codec | Bitrate (example) | Delay (MS) | Principal application |
|---|---|---|---|
| SBC | ~328 kbit/s | 200-250 ms. | Basic standard, compatibility |
| aptX | ~352 kbit/ | ~150-200 ms | Improved quality of music |
| aptX HD | ~576 kbps | ~200+ ms | Hi-Res audio, maximum quality |
| aptX Low Latency | ~352 kbps | 30-40 ms. | Video and mobile gaming |
The high definition version of aptX HD provides 24-bit audio with a sample rate of 48 kHz. This is a true standard for Hi-Res Audio wirelessly. However, it is worth noting that this codec requires a more stable connection and can be sensitive to interference in crowded air (for example, in the subway or shopping center).
AptX Adaptive is a modern standard that dynamically changes bitrates from 279 to 420 kbps (and higher in newer versions) depending on signal reception conditions and content type. If you watch video, it minimizes latency; if you listen to music in a quiet environment, it improves quality. Xiaomi smartphones based on Android 10 and later often support this adaptive standard.
How to check for aptX support on your Redmi
Smartphone makers rarely put information about supported Bluetooth codecs prominently in the specifications on the box or on the About Phone menu. At Xiaomi and Redmi, the situation is similar: you'll have to dig through the engineering menu or use third-party utilities to get accurate information.
The most reliable and secure way to do this is to use a specialized application from the Google Play Store, such as Bluetooth Codec Changer or Material Bluetooth Codec, which reads information directly from the system's Bluetooth stack, and then launch the app and connect compatible headphones, and the list of available codecs will show the ones that your smartphone supports.
An alternative method for advanced users is to use USB debugging (ADB), which requires a computer connection but provides the most accurate technical answer. You'll need an adb tool and run a command in the terminal:
adb shell dumpsys bluetooth_manager | grep -A 20"Codec"In the lead, look for lines that contain aptX, LDAC, or LC3. If the strings are present, then there is hardware and software support in your Redmi. You can also use the hidden engineering menu by typing in the "ringer" code ##8338## (does not work on all firmware), where you can see available options in the Bluetooth section.
⚠️ Warning: Do not try to change the values in the Engineering Mode unless you are sure of your actions. Resetting the Bluetooth stack settings can lead to temporary inoperability of wireless modules, requiring a reboot or reset of network settings.
☑️ Checking codec support
Instructions: How to activate and configure HD-sound
In most cases, Xiaomi automatically selects the best codec possible when connecting. However, sometimes the system gets stuck on the SBC codec due to pairing cache or priority errors. To force aptX or aptX HD to activate, you can use the hidden developer settings in MIUI.
To start, activate the developer mode. Go to Settings → About Phone and quickly click 7 times on “MIUI Version” (or “OS Version”). After the notification “You became a developer”, go back to the main settings menu, select “Additional” → “Developers”.
Inside the developer menu, scroll down to either Network or Bluetooth. Find Bluetooth Audio Codec. You click on it and you'll see a drop-down list. If your headphones support aptX, it'll be available to choose from. You can change Bit depth and sampling frequency.
- 🎧 Choose aptX. HD from the list if you want maximum quality listening in silence.
- 🎮 Choose aptX Low Latency or aptX Adaptive if you play shooters or watch videos without support for delay compensation technology.
- 🔄 If the desired codec is not selected (gray), then the connected headphones do not support it or the connection is unstable.
After changing the settings, it is recommended to disable Bluetooth and turn it on again to recreate the connection with the new parameters. Note that choosing a high-bitrate (HD) codec can increase battery consumption, since the processor requires more resources to encode the stream in real time.
Why are the settings resetting?
Comparison of aptX with LDAC and AAC in MIUI
Xiaomi owners often face a choice between different codecs. Apart from aptX, smartphones often feature LDAC (developed by Sony) and AAC (Apple standard), and understanding the differences will help you customize the sound to your needs.
LDAC offers the highest bitrate (up to 990 kbit / s), which is theoretically superior to aptX HD. However, it is extremely demanding on the quality of the radio signal. In a city with many Wi-Fi networks and other Bluetooth devices, LDAC can often “fall” to low bitrates, causing wheezing. aptX Adaptive in this regard is more stable, because it better holds the average bitrate values.
The AAC codec is the standard for iPhones. On Android smartphones, including Redmi, the implementation of AAC depends on the manufacturer. Often it works worse than in iOS, so if you use Apple AirPods headphones, they can sound mediocre on Xiaomi via AAC. iPhone owners are better focused on AAC, and Android owners with Sony, Sennheiser or JBL headphones are better on the aptX/LDAC bundle.
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For maximum music quality, use the FLAC or WAV file format. Streaming services like Spotify even at high settings compress sound (Ogg Vorbis), so the difference between codecs can be less noticeable than when listening to local Hi-Res files.
It is important to consider the support from streaming services. Some applications may limit bitrate at the software level, not allowing to unfold the capabilities of the codec. Check the quality settings in Spotify, Apple Music or Yandex.Music - there should be a "High" or "Hi-Fi".
Problems with sound delay and their solution
One of the common complaints users have is the de-synchronization of audio and video (lipsync issue) when watching YouTube or Netflix, as well as delays in games. This is directly related to the selected codec. Standard aptX and aptX HD have buffering, which creates a delay of 150-200 ms, which is noticeable to the eye.
To address this problem, Xiaomi smartphones with Snapdragon processors have aptX Low Latency (LL) technology, or the newer aptX Adaptive in low latency mode. They reduce response time to 40 ms, making latency virtually imperceptible. However, for this, both devices must support the standard.
- 📺 When watching videos in apps (VLC, MX Player) enable software correction of sound delay in the player settings.
- 🎮 In the game, use the Game Turbo mode. MIUI, which can prioritize Bluetooth traffic, reducing jitter.
- 🔌 Avoid using it. USB 3.0 devices near the Bluetooth antenna, as they create strong interference in the 2.4 GHz band.
⚠️ Note: If you use cheap Bluetooth transmitters for your TV, they may not support aptX LL, In such cases, delay is inevitable and can only be solved by replacing the transmitter or switching to wired headphones.
It’s also worth mentioning that some MIUI firmware has Bluetooth buffer-control bugs. If you notice the sound stuttering or lagging, try searching the developer menu for “AVRCP Version” and switching it (e.g. 1.5 to 1.4 or 1.6) to help stabilize the connection.
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There is no perfect codec: aptX HD is better for music in silence, aptX Adaptive is a universal choice, and Low Latency is only necessary for gamers and movie fans.
The Impact of Android Version and MIUI Updates
Support for codecs is not only hardware, but also software. With the release of new versions of Android (11, 12, 13, 14), Google is introducing native support for new standards, such as LC3 (Low Complexity Communications Codec), which is part of the Bluetooth LE Audio standard. Xiaomi Redmi smartphones that receive updates can purchase new codecs software.
For example, older models on Android 9 may not have a codec selection on the developer list, whereas after upgrading to Android 12, this functionality appeared, but the opposite happens: in some beta versions of MIUI, developers can temporarily cut out support for certain codecs due to instability, returning it in final releases.
Check system updates regularly in the Settings → About Phone menu. If you’re using Custom ROM (like LineageOS or Pixel Experience), make sure that proprietary blobs (Qualcomm’s closed drivers) are ported correctly, or aptX may not work at all, even on a powerful processor.
In conclusion, Xiaomi Redmi’s aptX technology is a powerful tool to improve the mobile audio experience, and the right setup and understanding of the limitations of your hardware will make the most of wireless headphones.