The issue now has a fix, and it should already be available to users. Updating a Sonos mobile or desktop app and then checking for system updates should push the changes to Sonos speakers.
A Sonos staff member writes that the Arc and Beam soundbars “in certain home theater configurations process Dolby MAT,” which delivers Atmos audio over HDMI connections. Sonos products could receive corrupted audio from that connection but were failing to filter out those bits, playing them instead. The corrupted audio “can manifest as a popping sound.” The Sonos devices’ improved Dolby decoder should no longer force listeners to hear what it sounds like when digital audio transmissions go awry.
As noted by The Verge, threads on Sonos’ forums, and writer Tom Warren’s experiences, suggest that the problem seemed particularly prevalent when an Xbox Series X or Apple TV 4K model was involved. Those devices use Dolby MAT 2.0 to issue Dolby Atmos audio to a TV connected to a Beam.
The Sonos staffer said the company apologized “for the disruption this bug has caused and want to thank you for your patience while our team developed a fix.” They also thanked the community for “detailed setup information and steps to reproduce the issue, which were helpful to us in uncovering the cause of the bug.”
The Arc is a soundbar that costs $900 (up $100 from its 2020 release price) and which prominently advertises “breathtakingly realistic spatial audio powered by Dolby Atmos.” The also-Atmos-ready Beam is $500. Given this, the length of the disruption, and the previously recommended fix to either disable CEC or use Dolby Digital 5.1 instead, many customers expressed disappointment. A Sonos employee, “Keith,” serving as a “Sonos emissary” on Reddit, acknowledged this problem but noted that the issue was difficult to consistently reproduce in Sonos’ labs, given the nature of it coming from interactions with third-party devices.
Scott Fink, product manager for home theater at Sonos, expanded on that difficulty in a response emailed to Ars Technica. “The bug was extremely difficult to reproduce, even when we replicated exact home theater setups of customers who reported the issue,” Fink wrote. “We also tested a wide range of solutions based on the early reports we received, ranging from TV setting adjustments to hardware replacements. As we received additional data we gained a much better understanding of the issue and were able to collect valuable insight and information that informed where we needed to focus our efforts.”
Responses at Sonos’ community forums so far have been generally positive, if critical of the delay. One noted that they had sold their Sonos equipment since the issue started. Another noted the fix was “Just in time for Black Friday too,” and wrote they were “Hoping to complete my setup with a sub gen 3 tomorrow too.”
This post was updated at 5:35 p.m. with comment from Sonos.