Key Takeaways

• Bluetooth codecs are software programs that enable audio transmission between your device and your headphones. They compress and encode audio data so that it can be understood by both devices, allowing you to hear your music.
• aptX, developed by Qualcomm, and LDAC, developed by Sony, are two common Bluetooth codecs. aptX is widely used in Android devices, while LDAC offers high-res audio but has limited compatibility.
• When comparing aptX and LDAC, LDAC produces the best audio quality at its highest bitrate, but it can be unstable when signal fluctuates. aptX Adaptive offers more reliable audio quality and lower latency, making it a better choice for most users. Consider your usage and device compatibility when choosing a Bluetooth codec.

Bluetooth headphones have become quite popular in the last decade, even more so since we (sadly) got rid of the headphone jack. And while you don't need to be an audio geek to use Bluetooth headphones, it's very useful to learn about the tech that goes inside them to know which ones to buy.

Let's learn about two of the most commonly used Bluetooth codecs—aptX and LDAC—that companies use to make their Bluetooth headphones work. We'll also compare the two to see which is better: aptX or LDAC.

What Is a Bluetooth Codec?

A Bluetooth codec is a software program that transmits audio from the source (your phone or laptop) to your headphones. It compresses this data to reduce its file size and encodes it in a format your headphones understand. Using the same codec, your headphones decode this encoded data so you can hear your music.

Simply put, a codec is a language that both your phone and your headphones understand and use to communicate with each other. That's why, for you to hear your music, your headphones (a Bluetooth receiver) must support the same audio codec as your phone (a Bluetooth transmitter).

You can check out how Bluetooth codecs work in greater depth if you want to learn more.

Bluetooth Audio 101

Before comparing aptX and LDAC, let's first understand a few necessary terminologies.

• Sample rate: The number of samples (pieces of data) taken from the original audio file in one second. It is represented with kHz or Hz. The higher the sample rate, the more accurate the sound reproduction. A higher sample rate generally means better audio quality.
• Bit depth: The number of digital bits (1s and 0s) representing a single sample. The bit depth determines the file size and is denoted by "bit." The higher the bit depth, the bigger the file size.
• Bit rate: The number of bits transferred from source to receiver in one second. It is indicated with Kbps or Mbps. A higher bitrate means better audio quality but also a larger file size.

You can learn more about bit depth and sample rate if you're curious.

What Is the aptX Bluetooth Codec?

aptX, an acronym for Audio Processing Technology, is a family of Bluetooth codecs developed by Qualcomm for wireless transfer. Its oldest version, aptX, was developed in 1980 and is still used in most Android devices. However, iOS devices do not use aptX codecs.

For a long time, wireless audio had a bad rep in the audio industry for its poor quality compared to wired audio. But this started to change when Qualcomm developed aptX to enable high-quality audio for wireless devices. Taking advantage of this, Sennheiser launched the first aptX-enabled Bluetooth headset in 2009—marking aptX's entry into consumer-grade headphones.

Since then, Qualcomm has released more versions of aptX to address various pain points in the audio industry. As of 2023, there are seven aptX codecs: aptX, aptX HD, aptX Adaptive, aptX Low Latency, Enhanced aptX, aptX Lossless, and aptX Live.

What Is the LDAC Bluetooth Codec?

LDAC was developed by Sony and was released in 2015. Sony brings both lossy and lossless technology together in the LDAC codec. LDAC was developed to enable high-res audio over Bluetooth paired with its adaptive bitrate. Due to this, LDAC doesn't have several variants like aptX, which makes the obvious difference between the two codecs.

Based on the signal strength, LDAC can switch between three bitrates: 330 kbps, 660 kbps, and 990 kbps. Given its capability to offer high-res audio, the Japan Audio Society (JAS) certified it with its "Hi-Res Audio Wireless" certification. Similar to aptX, LDAC is not available for iOS devices and is available on Android devices running Oreo 8.0 or above.

aptX vs. LDAC: Which Is Better?

In this section, for the sake of better understanding, we are only focusing on aptX variants that closely compete with LDAC.

Right off the bat, LDAC produces the best-sounding audio when it's on the upper end of its adaptive bitrate, i.e., 990 kbps. However, LDAC tends to suffer from unstable audio when there's signal fluctuation as it keeps switching between the three bitrates.

Another downside of LDAC is that when it swaps to its lowest bitrate, 330 kbps, it performs worse than the original aptX codec at 384 kbps bitrate. However, aptX HD, with its 567 kbps bitrate, falls behind when compared to LDAC's mid-tier 660 kbps bitrate.

In addition, aptX Adaptive offers a more reliable audio quality compared to LDAC. The former adjusts its bitrate freely within its range of 279 kbps–420 kbps as per the signal strength. The latter can only switch between its three pre-set bitrates—making aptX Adaptive a better choice to avoid sharp jitters in your audio, not to mention that it has lower latency, too.

Which Bluetooth Codec Should I Use?

When it comes to choosing a specific Bluetooth codec, there are a few considerations:

• Casual listening: For listening to music, you need a codec that offers high-audio quality that maintains consistency even if you're away from your phone. aptX and aptX Adaptive are great choices for this purpose. However, if you want the best sound possible, LDAC is the clear winner.
• Gaming: For mobile games like PUBG, codecs like aptX and aptX Adaptive are preferable as they offer low latency and stable audio quality.
• Watching videos: Similar to gaming, you need a low-latency codec to ensure both the video and the audio from your Bluetooth headphones or speakers are in sync. For this purpose, aptX Adaptive is more suitable than the rest.
• Making calls: For calls, you need good audio quality, so codecs like LDAC and aptX Adaptive are better choices. aptX Adaptive houses a feature called aptX Voice, specifically added to maintain clear audio during calls.

However, note that at times, even if you want to choose a specific codec, you might not be able to. For example, while you can switch between Bluetooth codecs easily on Android, the process isn't nearly as easy on iOS. Similarly, it's very difficult to change the default Bluetooth codec on Windows or macOS, even if you know your Bluetooth headphones support different options.

aptX vs. LDAC: Choose a Bluetooth Codec That Works for You

Bluetooth technology is still relatively new (in the grand scheme of things!), and it has a long way to go to stay on par with wired technology. This is why the differences between these codecs are very minimal and barely noticeable to untrained ears in real-time.

However, you must consider two things before buying Bluetooth headphones: your usage and their compatibility with your phone's codec. Once you are sure about these two, it's much easier to pick a pair of headphones.