Wireless And DSP Evolution
The Market Update article about Wireless Audio technologies featured in this issue revisits some of the extraordinary changes that have taken place in that space. But to tell all the stories and detail the technical progress, more than one article is needed.
It's particularly impressive how things have evolved in less than 10 years, and also the number of companies and technologies that have been left behind without ever gaining any consumer awareness. The distinctive factors and key features that distinguish winning approaches in wireless audio are not always obvious. Audio quality, the main argument for most Wi-Fi based solutions, explains why the technology remained at the core of the home audio segment. While convenience explains in great part why Bluetooth technology has evolved into the behemoth we know today — benefiting also from the massive size of the mobile market, where it originated and evolved. Bluetooth has meanwhile expanded to the home audio segment and is about to become even more recognized. For this issue, there was a lot to say about the evolution of Bluetooth, and next we will expand on solutions for wireless audio based on Wi-Fi and other technologies that deliver the much desired "wired-quality without the wires" and well beyond.
Bluetooth today doesn't address major requirements that in my opinion are decisive for mainstream consumer audio applications: audio quality, low latency, and synchronized multichannel. Any of those is a major challenge and it's been very hard to optimize products for two of those factors, without affecting negatively one of the three.
Most likely one of the features that consumers will quickly embrace in the renovated Bluetooth LE Audio specifications is Audio Sharing. If this becomes easily available and robust, it will make Bluetooth even more popular. But as the history of wireless audio technologies tells us, that's not easy to do based on standardized technologies.
For example, Multipoint connectivity, which Apple users have long enjoyed and is essentially described in the Bluetooth specifications, Audio Sharing, or the ability for a user to share its wireless stream with another user, is also something that Apple has made possible for at least three years — effectively introduced with AirPods and an iOS update without much fanfare. For some reason it's not available from a macOS device (e.g., an iMac or MacBook). But Apple pulled a few extra tricks to make the whole experience seamless when using an iOS device (iPhone/iPad) as source. Starting with the way it offers an option to "share audio" when the user is about to press Play, and includes the suggestion for the second user to approach its AirPods to the streaming source and guide the user to "pair" the second pair of AirPods (and it also works with Beats). Apple does it with a combination of standard protocols and a peer-to-peer link to achieve a very robust Audio Sharing connection, that currently the Bluetooth LE Audio specification describes but is not yet generally available. When it does, I am certain that wirelessly sharing audio from a source to two users — or more than two users with Auracast broadcast — will become something not only popular, but something that will again reinforce consumers perception of the technology's convenience.
In the sequel to the Market Update in this issue, I am discussing wireless audio for home theater 5.1 and immersive formats, which is still a challenge and it shouldn't be. Also, I will explore what is being done to address the bandwidth limitation of Bluetooth and enable real "lossless," or even uncompressed, high-resolution 24-bit audio.
This issue of audioXpress also features two important articles that reveal — each one in a different perspective — how important digital signal processing technologies are in today's audio industry. When I invited submissions for this issue focused on DSP, I was not surprised to see that the articles received all had voice in mind. The two examples included in this issue reveal how voice processing applications powered by artificial intelligence are determining what is possible today and in the future.
Having multiple synchronized 24-bit/96kHz audio channels with the lowest latency being streamed wirelessly should also happen very soon. What will trigger that evolution, we still don't know.