What is a Bluetooth audio codec?

In recent years, wireless earbuds, especially TWS, which work completely wirelessly and are really comfortable for the user, have become quite popular. The connection technology used by these devices is none other than Bluetooth. Their latest version has made the connection very stable and consumes very little energy. The sound quality has also improved significantly, especially thanks to the Bluetooth audio codecs available on the market.

It is precisely this last aspect that we will focus on in this article. Here we tell you everything you need to know about the current Bluetooth audio codecs. Likewise, we explain exactly what they are, what they are for, and what they stand out for. Let’s start!

Bluetooth audio codec: What is it and what does it do?

The first question we need to resolve before we continue is what codec is. This term is an abbreviation of two words: encoding and decoding. In essence, it is the normative framework or specification by which it is possible to encode and decode a data stream or signal. They can be developed using software or hardware.

The codec creates standard patterns that allow an operating system or an application to encode a multimedia file. This happens when we export an audio mix to a certain format or convert a file from one extension to another. In both cases, codec features are used to encode the file. Codecs are a way to standardize multimedia formats across all systems. Of course, that’s only half the job codecs do.

The second function is decoding. This happens when we try to edit or play a media clip. In this case, we perform a decompression that will only be possible if the machine and operating system can understand the file properties.

In short, they act as a standard protocol that allows you to compress, encode or create a multimedia file of a certain format. In turn, they also help the machine successfully open, decode or open the file.

Bluetooth audio codecs

At this point, you already know very well what we mean when we say codec. However, you may be wondering if what we’ve told you so far has anything to do with Bluetooth audio codecs. Codecs are responsible for encoding the signal emitted by the mobile device and decoding it in the headphones. In this way, these features have a strong influence on the quality of the transmitted sound.

It is important to note that in order to get the most out of a codec, both the signaling device (mobile phone) and the receiving device (headset) must be compatible. Otherwise, it will not be possible to benefit from each of them.

It’s time to learn about the most used Bluetooth audio codecs today. We explain what the strengths and weaknesses of each are.

SBC

SBC is one of the most basic features we can find today. In fact, we can define it as the minimum encoder to allow audio connections over Bluetooth. That’s why most of the devices offer compatibility with it. Essentially, this is its only advantage. Otherwise, it offers poor quality and poor understanding with a maximum bitrate of 328 kbps.

AptX

Similar to SBC, AptX is another story. This compression and decoding technology was developed by Qualcomm and its advantages include higher bitrate and lower latency. In its high-definition version, it supports audio resolution up to 24 bits and a maximum transmission rate of 567 kbps.

AptX Adaptive

AptX Adaptive is considered the successor to AptX. It is not very popular yet, but its features are worth it. It achieves a high bitrate between 279 kbps and 420 kbps. Also, according to Qualcomm, the latency is around 80 milliseconds. Another advantage is that it offers backward compatibility with previous codecs, AptX and AptX HD. This means that if the mobile device supports AptX Adaptive but your headset stays on AptX HD, you can use AptX HD without any problems.

LDAC

LDAC is one of the least lossy features in compression and decompression. This codec was developed by Sony and can be found in some of the company’s headphones. It offers a maximum sampling depth of 990 kbps and up to 32 bits at 96 Khz. An interesting aspect you should know about LDAC is that it is available on most Android devices since it has been integrated into AOSP since version 8.0. Unfortunately, it is not available on Apple phones.

LHDC

LHDC is another of those codecs looking for the best possible streaming quality. While not as common as some of its competitors mentioned here, it’s available on most devices updated to Android 10. As for the specs, it supports up to 900 kbps with 24-bit resolution at 96 Khz. One of the companies that preferred this was OnePlus, which included it in its high-end phones and headphones.

CCA

Up until this point, we’ve put the iPhone aside as its compatibility with different Bluetooth audio codecs is more limited. AAC is the standard that the Cupertino company offers on mobile devices. Technically it offers 320 kbps with 24 bit depth and 96 Khz. Although compatible with Android, this codec offers better sound quality on iPhone and iPad due to its integration with iOS. In terms of latency, it’s not very good as it’s below SBC.