When shopping for wireless headphones, you've likely encountered terms like LDAC, aptX, AAC, and SBC in product specifications. These are Bluetooth audio codecs—the software that compresses and decompresses digital audio for wireless transmission. While they might seem like technical jargon, understanding codecs is essential for getting the best sound quality from your wireless headphones. In this guide, we'll explain what codecs are, how they affect your listening experience, and which ones matter for your specific devices and preferences.
What Is an Audio Codec?
The term "codec" is a portmanteau of "coder-decoder." In the context of Bluetooth audio, a codec is responsible for two critical tasks: encoding audio on your source device (phone, computer, or tablet) before wireless transmission, and decoding that audio in your headphones so it can be played through the drivers.
Because Bluetooth has limited bandwidth compared to wired connections, audio must be compressed before transmission. The codec determines how this compression is performed—how much data is preserved, how much is discarded, and how the remaining data is organised for efficient transmission. Different codecs make different trade-offs between audio quality, latency (delay), and compatibility.
đź’ˇ The Key Concept
For a codec to work, both your source device (phone/computer) AND your headphones must support it. If they don't share a common codec, they'll fall back to the universal SBC codec, which offers lower quality.
SBC: The Universal Standard
SBC (Sub-band Coding) is the mandatory codec that all Bluetooth audio devices must support. It's the fallback option when devices don't share a higher-quality codec, ensuring that any Bluetooth headphones can work with any Bluetooth source.
While SBC gets a bad reputation, its quality varies depending on the bitrate used. At its maximum quality settings (328 kbps in "Dual Channel" mode), SBC can sound quite good—comparable to a 192 kbps MP3. However, many devices use lower bitrates for compatibility and battery efficiency, resulting in noticeable quality loss, particularly in the treble frequencies and complex musical passages.
The main limitations of SBC are its relatively low bitrate ceiling, which limits detail and dynamic range, higher latency compared to other codecs (typically 100-200ms), and more audible compression artifacts in demanding audio content.
AAC: Apple's Preferred Choice
AAC (Advanced Audio Coding) is the default high-quality codec for Apple devices and is widely supported across the ecosystem. If you're using an iPhone, iPad, or Mac with any compatible headphones, you're likely using AAC.
AAC offers significant advantages over SBC, including better sound quality at equivalent bitrates, more efficient compression that preserves musical detail, and native support in iOS without additional licensing. The codec operates at up to 256 kbps and is particularly well-optimised on Apple devices, where it delivers excellent quality with relatively low latency.
âś… AAC Best Practices
- AAC sounds best on Apple devices due to hardware encoding
- Quality on Android varies by manufacturer—some implement it better than others
- Excellent choice if your music library is already in AAC format
- Latency is generally acceptable for video watching but may not suit gaming
aptX Family: Qualcomm's Quality Solution
aptX is a family of codecs developed by Qualcomm that aims to deliver CD-like audio quality over Bluetooth. The aptX ecosystem includes several variants designed for different use cases.
aptX Classic
The original aptX codec operates at 352 kbps and offers better quality than SBC with lower latency (around 70ms). It's widely supported on Android devices with Qualcomm processors and many premium headphones. aptX provides a noticeable improvement over SBC, with better bass definition, clearer highs, and less audible compression.
aptX HD
aptX HD increases the bitrate to 576 kbps and supports 24-bit audio depth, offering "high-resolution" wireless audio. If you have high-quality source files (FLAC, high-bitrate streaming), aptX HD can reproduce more of that detail than standard codecs. The improvement is most noticeable in complex orchestral music, acoustic recordings, and content with wide dynamic range.
aptX Low Latency
Designed for video watching and gaming, aptX Low Latency reduces delay to approximately 40ms—low enough that audio and video remain synchronised. This variant is essential for gamers who need immediate audio feedback or anyone bothered by lip-sync issues when watching video content.
aptX Adaptive
The newest member of the family, aptX Adaptive, dynamically adjusts its bitrate between 279 and 420 kbps based on the connection quality and content being played. It combines the benefits of aptX HD's quality with aptX Low Latency's responsiveness, automatically choosing the optimal setting for your current activity.
LDAC: Sony's High-Resolution Champion
LDAC, developed by Sony, currently offers the highest audio quality available over Bluetooth. Operating at up to 990 kbps (nearly three times aptX HD), LDAC can transmit true high-resolution audio wirelessly, preserving details that other codecs must discard.
🔑 Key Takeaway
LDAC at its highest quality setting (990 kbps) is the only Bluetooth codec capable of transmitting audio at CD quality or better without significant compression. For audiophiles with high-resolution music libraries, it's the gold standard for wireless listening.
LDAC offers three quality modes: 990 kbps for maximum quality (best with strong, stable connections), 660 kbps for balanced quality and stability, and 330 kbps for prioritising connection stability over quality. Many devices automatically select the appropriate mode based on connection strength.
Originally exclusive to Sony devices, LDAC is now part of the Android Open Source Project (AOSP) and is available on most Android phones running Android 8.0 or later. However, your headphones must also support LDAC to use it—not all do, so check specifications carefully if LDAC is important to you.
LC3 and LE Audio: The Future of Bluetooth
LC3 (Low Complexity Communication Codec) is the new standard codec for Bluetooth LE Audio, the next generation of Bluetooth audio technology. LC3 promises better sound quality than SBC at lower bitrates, reduced power consumption for longer battery life, and support for new features like Auracast broadcast audio.
As of early 2026, LE Audio and LC3 are beginning to appear in new devices, but adoption is still in early stages. Over the next few years, LC3 will likely become as common as SBC is today, potentially reducing the importance of proprietary codecs like aptX and LDAC.
Which Codec Should You Use?
The best codec for you depends on your devices, music library, and priorities. Here's our practical guidance:
For iPhone users: AAC is your best (and often only) option. Fortunately, Apple's AAC implementation is excellent, and you'll enjoy high-quality audio without needing to think about codecs. Focus on choosing headphones with good drivers and acoustic design.
For Android users who prioritise quality: Look for headphones supporting LDAC, and ensure it's enabled in your phone's Bluetooth developer options. If your headphones don't support LDAC, aptX HD or aptX Adaptive are excellent alternatives that most Qualcomm-based Android phones support.
For gamers and video watchers: Latency matters more than maximum quality. Prioritise aptX Low Latency or aptX Adaptive, which dynamically minimises delay when watching video or gaming.
⚠️ Reality Check
For most listeners using streaming services at standard quality (Spotify, Apple Music's default settings), the differences between codecs are subtle. The biggest improvements come from choosing headphones with excellent drivers, good fit, and well-tuned sound signatures—not from chasing the highest-bitrate codec.
Checking and Changing Your Codec
On Android devices, you can view and change your Bluetooth codec in Developer Options. Enable Developer Options by tapping your build number seven times in Settings, then navigate to Developer Options, then Bluetooth Audio Codec. Select your preferred codec from those supported by both your phone and headphones.
On iOS devices, you cannot manually select codecs—the system automatically negotiates the best available option, which is typically AAC. Some third-party apps can display the active codec for informational purposes.
Understanding audio codecs helps you make informed decisions when buying wireless headphones and optimise your existing setup. While codecs are just one piece of the audio quality puzzle—source quality, driver design, and acoustic engineering matter too—choosing the right codec ensures you're not leaving quality on the table in your wireless listening experience.