After Bose released updated firmware for its QC35 II headphones last year, users complained on the company’s forums that the headphone’s active noise cancellation had gotten a worse. Now, the number of complaints has ballooned to fill more than 200 pages in the forum, and even though Bose says its software isn’t the problem, the company is allowing users to downgrade their headphone’s firmware.
Issues first cropped up last summer after Bose released firmware version 4.5.2 for its QC35 and QC35 II headphones. While it seems not every user was affected or noticed a change, others complained the update caused a drastic decrease in the effectiveness of Bose’s ANC tech, with some QC35 II owners even saying that “the ANC on high level is now the same as in LOW. I can not hear any difference when i toggle between them now. The same amount of sounds go through to my ears.”
Late last week, Bose posted a response detailing the issue and what it has done to identify and investigate it. Bose says that after thorough testing, the company is “confident that firmware 4.5.2 did not affect the noise cancelling feature.”
Bose says it reached this conclusion by testing a number of headphones using different firmware, inspecting headphones returned to company, and even sending acoustic engineers out to perform five in-home visits. In the end, Bose found that eight of the 10 devices it tested in-depth were functioning properly. In a number of cases where a user complained about ANC not working properly, Bose discovered that things like third-party earcups or earcups not being snapped in properly, apparently causing the perception of weak ANC performance.
Bose says that in one only case did its engineers find a pair of QC35 IIs where there was little difference between setting ANC to high or low, which ended up being caused by mechanical damage, most likely from general wear and tear as the owner “noted that they did not use the case to store and transport their headphones while commuting every day.”
While Bose says it “could not attribute any noise reduction performance loss to the QC35 4.5.2 firmware,” it says it did learn some things from its investigation and came up with a few solutions on how to address certain issues.
First, to better educate QC35 owners on how to properly use and maintain their headphones, Bose created a new package of instructional videos and documents. Second, it’s updated its messaging around updates to more clearly explain the difference between updating firmware versus updating Voice Prompts.
Finally, Bose will also now allow users to downgrade the QC35 and QC53 II’s firmware via the Bose BTU site, which is an option that was previously unavailable.
So while it seems the firmware was not the real cause of degraded ANC performance in the QC35s, at least some good did come out of a nearly yearlong investigation.