December 2024

Wireless Audio Roadmap
New scalable codecs plus increased bandwidth will ensure better sound quality.
Editorial By J. Martins

  Wireless audio is truly remarkable. Whenever I use my smartphone to play music on earbuds, in the middle of a busy street or on a plane, and I hear the music, the experience never ceases to amaze me. When I'm not at home, it's likely I'm streaming from a cellular network service directly to my smartphone, and using Bluetooth to stream from that device to two "true wireless stereo" earbuds or to headphones. (I previously downloaded my favorite music, but these days with 5G, most consumers just press play and never stop to think about how the "magic" happens.)

In the audio industry, we tend to criticize Bluetooth for being the last link that still forces us to hear music in compressed form, disregarding the fact that the stream was playing from a central repository somewhere on the other side of the continent, or even in another country, and passing through a complex maze of network servers and cellular links until it reaches our devices. Chances are if we are playing the latest hit from Lady Gaga, that the stream is coming from a server close by, but not a chance if I have just selected my favorite obscure track from Killing Joke. And every time we move, the streaming service is relayed from different cell towers, multiplied by thousands of streams of people moving, some of which are streaming YouTube videos or endless TikTok clip-swiping. And we still sigh because we're not getting the full 24-bit/96kHz master streamed to our Bluetooth earbuds....

It is different at home where we can rely on good-old fiber and Wi-Fi 6E gigabit-speed network to stream those wonderful hi-res masters, correct? Wrong. While stream buffering usually allows enough margin to have an interrupted listening experience, quite often, depending on the service selected and how obscure the music selection might be, it's very easy to suddenly see a spinning circle before the music starts playing or have interruptions during play. A downgraded 24/96 hi-res Max mode to 16-bit FLAC or from FLAC to 320kbps AAC usually solves the problem, and the music resumes.

Of course, the experience will differ when using Spotify or Tidal or Qobuz or Apple Music, and depending on the network access and even region of the world. But during my travels, I've learned to recognize how consistent the music streaming service can be, even on a hotel Wi-Fi. The experience is miraculous and gives us a valuable perspective about how good streaming technology and telecom services are in 2024. We are truly spoiled – most consumers who never download anything or care about how things work certainly are.

At the core of our music streaming experience is inevitably Bluetooth wireless technology. And Bluetooth is now evolving with LE Audio, offering us low-power solutions that make batteries last longer and actually improve fidelity and consistency of the experience by replacing the dreadful original SBC codec with the much more efficient Low Complexity Communication Codec (LC3) algorithm, now provided as the default codec for Bluetooth Low Energy (LE) Audio.

Many of us who care about audio have learned over the years to rely on a complete AAC codec chain for our Bluetooth Classic streaming, and some have even made the effort to make things work with aptX or LDAC codecs. AAC technology, like the new LC3, is the result of extensive research conducted by the experts at the Fraunhofer Institute for Integrated Circuits (IIS). That's where the AAC and HE-AAC codecs originated, as well as a fourth generation of best-in-class audio technologies that includes MPEG-H Audio, EVS, LC3 / LC3plus, and xHE-AAC – all of which elevate media experience to new heights – particularly over wireless technologies.

The roadmap ahead will allow us to benefit from this new generation of highly effective codecs, which also include new scalable codecs that will improve the service provided at the infrastructure level. Bluetooth is not stopping here, and soon, High Data Throughput specification updates will enable data rates up to 8Mbps. Bluetooth LE Audio will also evolve to support lossless codecs, high-resolution audio, and even multichannel formats. This means Bluetooth will no longer be the bottleneck limiting the quality of our listening experiences.

J. Martins
Editor-in-Chief

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