Being able to wirelessly connect headphones and speakers to your phone or computer is a magic many of us take for granted. It wasn't that long ago that the idea seemed impossibly futuristic. These days, you can get true wireless Bluetooth earbuds for less than a meal at McDonald's and BT speakers that can blow you out of the room.
But there's more to Bluetooth than a simple wireless connection. Bluetooth is the conversation, but the codec is the language being spoken. In the early days, high-fidelity audio seemed just as impossible as wireless had only a few years before. Today, a range of codecs promises audio quality the MP3 era could only have imagined.
Not every headphone or earbud can understand every codec that's out there. Not every source, like your phone, laptop or portable media player, can transmit every codec, either. So here's what they all mean, what you might want to consider and -- most of all -- whether any of it really matters.
What's a codec?
This diagram, via Sony, illustrates the challenge of sending audio data wirelessly to headphones. With hi-res -- and even standard CD-quality -- audio, the data must be compressed to fit through Bluetooth's limited "pipe." Streaming audio, including compressed formats like MP3 and AAC, is re-encoded again for wireless transmission. And for a more stable Bluetooth connection, lower bit rates are generally more reliable. Sony
"Codec" is a portmanteau of coder/decoder. A source encodes some data, and on the playback side (your headphones, say), a decoder converts that data into a form it can use. Nearly everything we use in the modern digital world uses a codec of some kind. Talking to your friends on the phone, watching Netflix, listening to Spotify -- there's some kind of codec at work.
There are countless types of codecs across different technologies, and Bluetooth has several possible codec options of its own. Think of Bluetooth as a phone call between two people: They might speak French, English or even Klingon. Bluetooth is just the connection -- the language they use is the codec. There's more to it than this, but that's the general idea.
Conveniently, deciding the codec "language" is usually done automatically once you connect the devices. Your phone and earbuds, for example, will do a little handshake -- an agreement on which language they'll speak. In some cases, you can force them to speak a different language, but I'll talk about that in a moment.
While the end result -- music in your ears -- is the same, the various codecs differ in important ways. One important aspect we'll be discussing is bit rates, essentially how much data is used per second to transmit the audio. Think of it as the size of the pipe, so to speak, between your earbuds and phone. A bigger pipe is often better, but not always. I'll dive into that, too. And keep in mind that these codecs are separate from the ones used to encode the music originally. Even though some share the same names, these codecs are specifically for the wireless transmission of the audio.
The basics: SBC and LC3
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