QC 35 II Firmware 4.5.2 Official messages

2 April 2020


Hello everyone,


I wanted to thank everyone who participated in this discussion. I just posted a summary of the investigation we did on the reports here and encourage everyone to read it. It's a full summary of everything that was done and I hope you appreciate it.


Afterwards, you can participate in a discussion around the report at this thread.


Once again, thank you to all our community members who helped us by providing detailed reports of their experiences with firmware 4.5.2.


24 January 2020

Hey everyone!
Apologies for the recent lack of updates. At this point I don't have any additional news to provide other than we are continuing to work on this. We have received some headsets from customers and are in the process of analyzing them. I hope to have a more detailed update at a later time. 
As a reminder if you are unhappy with any of our products, for whatever reason, please contact us here.
Wayne M

3 December 2019


I don't have any new information to share at this time but we are continuing to work on this.


Right now we have a very multifaceted approach. We are paying attention to this thread and the concerns being brought up in it, as well as listening to your feedback with regards to the firmware and functionality you would like. We are continuing to visit with willing members who filled out the survey to run tests and better understand the reports of ANC changes and reviewing QC35s that have been sent to us.


I also wanted to add a reminder that we want to make sure that you are enjoying your Bose products. If you are unhappy with any of our products, for whatever reason, please contact us here. Everyone's circumstances are different, but we will always do our best to make sure you are satisfied.


I'll get everyone more information once I have it!


-Wayne M


21 November 2019


Hey everyone,


Thank you again for taking the time to complete the survey. The strong participation we received is much appreciated and we have now reached out to all respondents by phone. It has been great to talk with many of you and to learn about how you use your QC35 headphones. These conversations have been productive in helping us understand the difference in ANC many of you are reporting.


We are still in the process of planning more visits in the coming weeks, prioritizing members still in possession of their QC35s as some of you have already received replacement units and are no longer experiencing the issue. We’ll continue to provide further updates on the status of these visits as well as our next steps once the process has been completed.


Thank you everyone who continues to work with us and support us as we investigate!  


I apologize for any confusion but I do not have any information about a new firmware release at this time.


1 November 2019


Hey everyone,


I wanted to once more thank everyone who took their time to fill out our survey. At this point, we feel we have a good number of respondents, so we are going to turn off the survey on Sunday, November 3rd at 12:00 PM EST (4:00 PM GMT).  


We will continue to reach out to qualified individuals who fill out the survey prior to that time in the coming weeks.



Wayne M


16 October 2019


Hey everyone,


Thanks for the continued posts on this thread. Some points have come up that I want to address.


Marked as solved

I appreciate the feedback on this and thanks to everyone who commented. My intent was to make the survey more visible and only that, but after reading the comments and listening to your feedback, I have removed the survey post from being the solution. I have added the survey post to the sticky thread 'QC 35 II Firmware 4.5.2' in hopes that more people will see it.


I apologize for any confusion that resulted from this and want to clarify it is possible for a solution to be updated.


What did we learn from our visits?

The biggest item we were able to take away from the home visits so far were new test cases for our engineering team to take a look at, particularly around the way that users update firmware. As a result, we modified our procedures to accommodate these new findings and conducted extensive testing. Even though testing completed without issues, we’re encouraged by this finding and excited to visit more users so that we can uncover more possibilities.

Coordinating these visits is no small task, as the process between initial contact and the first visit can be extensive. We are still trying to coordinate more visits and have been responding to survey participants, usually within 24 hours of completion. Thank you to everyone who has filled out the survey and I encourage anyone who is still having an issue with the ANR performance of their QC35 product after a recent firmware update and is willing to talk to us to please fill out this survey! 


At this point, it is still too early in the process for me to go over more details of the visits. Once we have done a few more and have concrete information to share, we will.   

Bose updater (

As some of you noted, with this recent update to the BTU site, we have made a number of enhancements to the security of the updater and how it functions. These changes are being made to address identified security concerns as part of our commitment to delivering secure products and services.


Next steps

We are continuing to schedule home visits as quickly as we can. Our internal testing is also continuing. Additionally, we are looking into implementing other changes, such as ways to give you additional control to better manage your product so that it works the way you want. It is still too early for me to discuss these here, but we hope to update you again soon. I know many of you have been waiting a long time, so I want to assure you that as soon as I have additional details to share, I will.


Wayne M


10 October 2019

Hey everyone,


I know it has been a little while since someone at Bose has given an update, so I want to assure everyone that our Engineering and Service teams remain dedicated to getting to the bottom of what’s going on here. 


So everyone is aware, earlier this month we reached out to users to schedule visits to their home so the Engineering Team could test the QC35IIs in a live setting. We learned some new information from those members we spoke with, but are looking for more of you who might be willing to talk with us about your QC35IIs.


If you are interested in talking with us, please click the survey link below.




We are looking for users within a reasonable distance from our Bose offices in Massachusetts who are willing to let us visit their homes and test your QC35IIs. If you qualify, we may reach out to you via phone call to discuss further possibilities, including a potential home visit.


Thank you everyone for your continued posts and assistance as we continue to work through what is going on here. I will make sure to have more information for you soon.


-Wayne M


2 September 2019


We’re back with an update.


First, thank you for being here. We’ve read every post, and will continue to.


We’ve also continued to exhaustively test QC35IIs to find the problem you’re having with the latest firmware update, including the handful of units you’ve sent us – which we’ve replaced with a new pair. We have a dedicated team working on your complaints every day, all day. Despite that, we haven’t been able to duplicate what you’ve described. We’re sorry. But we’re not giving up.


We’ve asked Bose employees to let us know if the firmware update impacted their headphones, because there are thousands of us who own them just like you do. We haven’t received any reports back from inside Bose, but hope we do. It will help us get to the bottom of it.


We’ve also contacted some of you to ask if we could come to your home, and test your QC35 II, with your phone, in your surroundings. We’ve started making arrangements and are clearing our schedule to accommodate theirs.


There are a few things you can expect next. First, we won’t identify who they are, because that’s not up to us. It’s up to them. But we will communicate what we learn. All of it. 


Until then, our research continues. And our commitment to you does, too.


Your Community team on behalf of the Bose QC35 II Engineering Team



2 August 2019


Hello everyone,


As noted in the master thread HERE, we've decided to make one central location for all main updates within the thread. We'll be updating this post when we have news to share. At present, we are asking a few more of you to send us your headsets so we can continue testing. If you have reported an issue and would like to participate in our investigation, please let us know in this thread and we will contact you via private message. Please note that for logistical reasons, only users based in the USA can volunteer to send in their headset. We would like to thank you in advance for your cooperation.


Your Community Team


31 July 2019


Again, we would like to thank you all for your patience.


As communicated previously by our moderation team, we have confirmed that no changes were made to ANC as part of the latest firmware update and that no impact was detected during quality assurance testing. However, we asked a few users who reported an issue to send in their headsets so that our Software and Hardware teams could investigate.


The quantity at which we have received is not what we would have hoped for and we will be asking a few more of you to send us your headsets so we can continue testing. If you have reported an issue and would like to participate in our investigation, please let us know in this thread and we will contact you via private message. Please note that for logistical reasons, only users based in the USA can volunteer to send in their headset. We would like to thank you in advance for your cooperation.


Once again, thank you for your assistance and your patience.


Your Community Team



17 July 2019


Hello All,

First of all, we would like to thank you all for your patience.

We would like to take this opportunity to reiterate that no changes to the software for active noise canceling or ANC modes were made as part of the firmware update and no impact to ANC was detected during our validation testing. Our validation testing is a comprehensive process which is part of all firmware releases. We have revisited our test records and confirmed there were no changes to ANC. The way our testing was done was by using several QC35 II headphones across the latest firmware releases and measuring the ANC under the same conditions for each setup. No changes were noted.

As communicated previously by our moderation team, we asked some users who reported an issue to send in their headsets so that our SW and Hardware teams could investigate.
We did receive several units and preliminary tests show no change in the ANC. Our team has so far been unable to replicate the problems stated here. However, please rest assured that we will continue to test the headsets, which are instrumental in our investigation of this reported issue.

We will keep you updated as soon as more news becomes available.

Once again, thank you for your assistance and your patience.

Your Community Team



5 July 2019


Hi all,


We'd like to personally thank all the users who have so far returned, or volunteered to return, their headset to our development team for investigation. These units are being used to assess and evaluate your concerns, and we'll be sure to post here when we have feedback or news to share with the Community.


In the interim, we would like to highlight that we do not encourage attempting to downgrade the firmware of your headsets, as this could lead to damage of the headphones. All current product firmware should only be delivered via the Bose Connect application or BTU portal. You can find more information on why downgrading the firmware for your Bluetooth product is not supported in the post HERE.


We thank you for your continued patience.


Warm regards,

Your Community Team



26 June 2019


Dear all, 


Thank you for your continued patience in regards to the reported change in ANC following Firmware update 4.5.2.


We have looked into this extensively for you and have escalated this to our engineering team. They have been able to confirm that no changes were made to the ANC functionality in the most recent update.  That said, we want to make sure we are supporting those who may still be having issues and may be reaching out to some of you directly for more details to support a continued investigation.  


There are a number of troubleshooting steps you can take regarding ANC that can be found below:  We encourage you to review it for a potential solution.


  • Be sure the headset is turned on. The switch on the right earcup should be in the "On" position with the green LED illuminated. The headset must be turned on to cancel noise.
  • Double check that the cushions are securely attached to the earcup. If the ear cushion is not affixed to the ear cup properly, the noise reduction may be affected.
  • Check to make sure the headset is fully seated and the ear cushions are in good shape as the seal they provide is extremely important for noise cancellation performance.
  • Verify the noise cancellation mode you are in through the Bose connect app. 
  • Complete a product reset.


Further support may be best handled directly, rather than through the community.  To find the contact information that you need, you can use this link.  Just select your country and scroll down to where you see “contact us”.    


Thank you once again for your patience. 


Warm Regards, 

Community Admin

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