What is a Bluetooth codec (AAC, SBC, AptX)?

A Bluetooth codec affects sound quality. Want good sound? Then it's worth checking the codec your Bluetooth earbuds, headphones, or speaker use. But which codec is good?

What is a Bluetooth codec?

A Bluetooth codec is a code that can represent and transmit sound. It's essential for Bluetooth devices to transmit audio.

Think of it as the language used to package your audio (music, podcasts) and send it from your phone (or laptop or tablet) to your Bluetooth earbuds (or Bluetooth headphones, Bluetooth speaker, etc.).

The image above (created by Eardopes) shows that there are different types of Bluetooth codecs. The most popular codecs are AAC, AptX, and SBC.

When you listen to Spotify on your phone through Bluetooth earbuds, your phone doesn't transmit sound the way your voice does. Your phone and wireless earbuds have effectively agreed on a language (a codec) to send the audio.

That might seem like a simple comparison, but a language works like a codec. AptX and AAC are simply ways to represent something.

The sending device encodes sound according to a particular codec. That code is sent over Bluetooth. The receiving device (the earbuds or headphones) receives the code. The Bluetooth earbuds recognize the codec and decode the data so they can play the sound through the speaker.

What is the best codec?

It's hard to say which codec is best overall. It depends on how you use it.

Do you want to use Bluetooth for communication, listening to music, or gaming?

When listening to music, you want as little quality loss as possible. For calls, you want the fastest possible two-way transmission. For gaming or watching videos, you want minimal delay.

The best audio codec is AptX. At least when it comes to sound quality. Want low latency? Then AAC, or better still SBC, is a better choice. AptX Adaptive is a new codec from Qualcomm designed specifically to reduce delay. Simple codecs are faster and easier to transmit. AptX Low Latency is a new codec from Qualcomm that performs very well for Bluetooth communication. It offers low-latency two-way communication.

Best codec for high sound quality

AptX is a very good codec for preserving sound quality. But AAC is also a very good codec for top sound quality. And it's a little faster, too. AptX is relatively old, while AAC is somewhat newer.

Best codec for communication

AptX Adaptive and AptX Low Latency are good codecs for calls and video meetings. AAC is also a good codec for calls. SBC is another good choice because it's very lightweight. Especially on long calls, SBC can help your battery last longer. The downside is that SBC has a little more delay.

Think about it: communication needs to go both ways. A Bluetooth earbud has to decode and process the incoming sound (the code), then play it through the speaker.

At the same time, the earbud has to pick up your voice through its microphone. That signal needs to be encoded so it can be sent to the device, such as your phone.

So during Bluetooth communication, the signal travels in two directions. At the same time. That takes quite a bit of processing power. It all happens in the processing center of the wireless earbud or Bluetooth headphones: the chipset.

Best codec for low latency

AptX Adaptive is a codec with very low latency. Qualcomm specifically developed it to reduce delay.

And it worked. When gaming, it helps to have as little delay as possible. So it's important that your headset or earbuds use a low-latency Bluetooth codec. AptX Low Latency, for example. You just won't find many Bluetooth devices with this codec yet.

Different types of codecs

There are many different Bluetooth codecs. But 3 are used most often: AAC, AptX, and SBC. They're used by 98% of all Bluetooth devices.

AAC

AAC (Advanced Audio Coding) is a popular Bluetooth codec. It's better than SBC. Hence the word advanced.

You'll often find this codec in more expensive earbuds, headphones, and speakers. Although the codec has been around since 1997 (!), it has only become more popular in recent years. At least for transmitting audio over Bluetooth. As an audio file extension, AAC goes way back to the Britney Spears days. You might even have downloaded ups_i_did_it_again.aac through Kazaa at some point. If you have no idea what I'm talking about, you're probably around 20.

The advantages of AAC: it preserves more of your audio quality than other codecs. It can package your music into very simple code while still delivering plenty of sound quality. That's something we like at Eardopes. That simple code also uses less battery power, so you can listen to music longer.

AAC is also a widely accepted codec. Many companies and platforms support it, including Apple's iOS and iTunes. In short, AAC is often a good choice. And every phone can handle AAC.

Are there any downsides to using AAC as a Bluetooth codec? Not many. Older devices often can't handle AAC. But they can't handle other codecs either. So that's really splitting hairs.

AptX

AptX is another popular Bluetooth codec focused on preserving sound quality. Unlike AAC, AptX specifically aims to improve the quality of wireless devices, such as wireless earbuds, headphones, and speakers.

AptX was developed by Qualcomm to improve sound quality compared with other codecs, without compromising stability or latency. And Qualcomm has largely succeeded.

That makes AptX an excellent option if you want smooth, fast audio transmission over Bluetooth.

There are a few variants of AptX:

• AptX HD (for HD streaming)
• AptX Adaptive (for very low latency)

SBC

SBC is a codec usually found in more affordable earbuds, headphones, and speakers. It's easy to use in lower-cost devices.

The advantage of this codec is that it compresses audio into a very small, efficient file. That makes it easy to transmit, and your device uses very little power.

But it also means the sound quality isn't as good as with AAC or AptX. Well, you can't have everything.

Do earbuds or Bluetooth devices only have 1 codec?

No. Bluetooth devices can support multiple codecs. Your earbuds might have SBC + AAC, for example. You can then choose between them.

How? Like this:

Go to the Bluetooth settings on your Android phone, for example. Then open the settings for your earbuds (or headphones or speaker) and move the switch to the right to change from SBC to AAC.

Conclusion

Buying earbuds or another Bluetooth device and wondering which codec is right for you?

If you're particular about your music, go for AAC or AptX. These are the codecs you'll often find in slightly more expensive earbuds.

Prefer to spend less? Then earbuds with just SBC are a better choice.

Others also viewed:

• Browse all our articles about wireless earbuds
• These are the best earbuds under €50
• These are the earbuds with the best microphone
• Also check out the best earbuds for running