Bose QC 35 Firmware 4.5.2 Noise Cancellation Investigation Discussion in Around & On-Ear Headphones


I saw similar thread about ANC investigation, but anyway..

Purchased QC 35 a week ago. Was amazed by quality, it allowed me to work at home without hearing children around... Well, for 2 days. Then I installed Bose app, it upgraded firmware, and after this update I can hear all voices around (low-frequency noise is still blocking well). Even silent voices! Which was not a case before upgrade. Only after that I have found these forums, "investigation" results, tons of complains, etc. Tried to exchange headphones but local seller said that it is not warranty case, I wasn't able to proof that.


Asking to help to get back to initial firmware version (3.1.8, or something like that). I see that one day there was an option to downgrade, but now it is not available. Can someone please help? Experience fully ruined, like 2 different products, first is perfect, second is something which I would never buy. 😞

Joined to look for a solution. I flew on an airplane and was good, I had an hour to kill at the airport and I updated the firmware and the next flight noise cancelling was not working.  Looks like I am one of the unlucky ones that has a pair of expensive noise cancelling headphones that no longer cancel noise.  Is there a way to go back with the firmware?  obviously someone is in denial with this problem.


It’s very frustrating. I have a brand new pair and I can hear everything even if the volume is high. Please Bose, respond to this problem, give us something. It’s been one year and nothing from you

I do not work for Bose. In 2018, Bose's policy changed and they began only supporting only the current version of the firmware.  For a very short period of time when this discussion first came out, they offered another earlier version but from what I read in this community, it had mixed results.  I believe that option is now gone but have not myself checked.   Bose does not like customers here to discuss regressing the firmware as its their copywritten property.  Many of us find that as 'strange' since there are 9 firmware versions probably on many different QC35ii's - though Bose will tell you that to support the QC35ii they will first ask the users to upgrade the firmware.  It is quite 'obvious' 🙂 on figuring out how to do what you want via other googled sites.

You can try upgrading once or twice more using both method (connect and web) though your prospects of restoring your ANC are not good.

Bose of course did an extensive investigation (hence this thread) and was unable to verify any of the customer claims that firmware has anything to do with a change in ANC and as far as I know that investigation is completed with nothing to say it will be reopened in the future.  I personally at this point technically believe it is neither firmware or the upgrade process specifically but rather involves perhaps units with malfunctioning chipsets (i.e., chips that are supposed to provide a specific set of values to a 'stimulus' and are rather providing different values not anticipated by the firmware.  That could account, for example why your unit upgraded to 4.5.2 and had an immediate difference, while a unit like mine upgraded to 4.5.2 both via the web and connect and still performs fine.

Another possibility you may want to try as it 'could' be a hardware issue is to exchange the unit with the retailer you purchased from or Bose if it makes financial sense to you as the exchanged unit may be on a different firmware and still work.  Then from that point on, always use Bose Connect app after putting your phone in airplane mode.


Thanks joelirwin for taking the time to reply.

My unit is probably 18 month old now so will be out of warranty no doubt.  if there is no "fix" on offer from Bose then it will likely be the last Bose product I purchase.

So many people with the same problem but no acceptance that there is a problem to fix is frankly in my opinion a disgrace.  

Hey guys, I’m still on 1.3.4 and was just away to click the update, then read all the feedback on here regarding the latest corrupt firmware, I presume I should not click update at all as I love my NC headphones and don’t want this spoilt by Bose disregard to listen to Customers who purchased (in good faith) their products....probably never again by the looks of things.


So stay on 1.3.4 or take the leap of faith? 

I have the AE serial and from UK

I'd stay. Why break a thing that isn't broken 🙂

Yep your right 🙂 

As of yesterday, I sent my QC53II back to Bose. Overnight the ANR stopped being as effective as it was when I first bought the set.


I haven't been actively updating the software, but either my wife or I did accidentally a few days ago. For info, I haven't been updating the firmware simply because I "plug and play" and don't tend to use the Bose Connect app. It's only when my wife started using them only a few days ago, that I used the App.


The ANR was so good before that I could work and not be disturbed.


My daily (lockdown induced walk) was bliss because I would put on the QC35II, and walk without being disturbed - listening to very quiet radio chat or music. Nothing would get past the ANR. I live next to a busy main A-road town bypass, even walking along that I would have to be very careful to keep a lookout for cars as I would not hear them.


Overnight, the ANR effectiveness was reduced. Wearing them around the house to work, I have noticed more ambient noise. When walking in the same places (daily walk remember) the ambient noise is much more pronounced - cars, footsteps and even bird song get through. Things that I have never experienced before when wearing the QC35II.


A poster mentioned above that it is likely (in their opinion) that people are jumping on the band-wagon after a minority of complaints. In my case, both my wife and I noticed a reduction in ANR quality and that then prompted my search for any reports and potential issues. Hence, I stumbled onto this thread.


I appreciate the amount of work that Bose and their Engineers have done to investigate and so far I have been impressed with the return and replacement policy. However, I'm dreading that the new replacement will have the same issue.


I take care of my headset, and it lives in the carry-case when not in use.

The cushions are in very good condition.

I have executed all the trouble-shooting advice to no avail.


The ANR toggle in the Connect app makes little difference when toggling from "low" to "high" ANR. "OFF" works, "OFF" to "low" engages ANR but essentially "high" makes very little difference anc certainly not back to the original ANR.


Is Bose still looking into this issue or is "case closed" and no further fault found?


Kind regards


(PS I can forward the S/N of the returned headset if required as well as the UPS tracking info if needed)

An update just in case anyone is interested:

So, I sent my original pair of QC 35II back and just received the new ones. The set is running Firmware version 4.3.6 with DOM of 15 July 2020.


Once again, the toggle (in the app) to high NR achieves very little noticeable change.


When I first bought these: I couldn't hear my laptop keyboard when I typed (and it's a very quiet keyboard anyway). Walking along roads etc I could hear very little of the outside world (not even passing trucks) but now I can hear birdsong even when on high ANR. The noise reduction is still not as good as it was when I first bought the original pair. To say that I'm disappointed is an understatement.


Before anyone asks, my hearing is tested every two years for my job. It is very good and sensitive.


Also, I'm not especially wanting to jump on any "bandwagon" etc - I just want the product to work as it did when I first purchased it. Incidentally, A friend has bought the Qc35 II IN EAR set. He stated that the ANR was brilliant and that when he was wearing them, nothing (noise) could get past them - So I gave them a go.... and yup, they are just like my original pair. So what has changed? Are they running the same software?


I'm now considering my options - I think that I should be able to return the set for a full refund




I see Bose have been offering replacement products for recent purchases. That's cool, even though there's plenty of people noting this haven't solved the issue completely. What's even more sad are customers like me, who's already out of warranty period thus there is literally no solution provided by Bose. If there's a common issue with your products, you don't choose to help only the customers who has active warranty and you are legally obliged to help - if you are a good brand which deserves a price premium - You rather care about your brand image and the satisfaction of all your customers who pays a considerable amount of money for your products - if you want them to keep paying -


1. Only solution offered, purchase a new one. Hilarious as conditions are: 1) send us your current device 2) pay EUR 240 on top of it. It's hilarious because they can be purchased for ~EUR 200 online without any effort nowadays.

2. No service or check is offered. Customer representative told me Bose doesn't do that because these are hygiene products. Shout out to Bose, these also happen to be the products you produce so I'd highly recommend against producing anything that you're not willing to service.


Based on these two points, I can't help myself to believe the allegations that this is planned obselescence. 


Does it ever occur to Bose that some of their products may be defected or started malfunctioning for a reason including potentially the firmware? How can you refuse to take a look at the product, test and service it if possible while it clearly performs way below than before, for what it was payed for.


I'm sorry Bose but I won't keep paying a couple of hundreds of euros every 2-3 years to maintain a single set of headphones. The way you're managing this situation just makes you lose your customers for a lifetime.


In a nutshell, the headphones I payed EUR 300 for is literally junk now. I could use them only ~2 years properly and only path forward is to live with this loss and switch to another brand without looking back ever again. Such a disappointment.


Edit: Got a small conversation with Bose Service account on Twitter. It came to the solution of buying a new pair of NC 700 with a discount (which is not actually a discount as I can keep the current pair and still pay less to get a new NC 700 elsewhere online). So, the EUR 300 payed headphones stops functioning properly in 2-3 years, the manufacturer doesn’t offer any chance of examination/repair/service for something which is highly likely that their fault, and solution is to buy a new pair. This just strengthens my opinion about what this is all about.




I was wondering if you were able to get this resolved?  I am now experiencing the exact same problems you reported (even down to picking up on the Keyboard noise and birdsong).  This happened as soon as I updated the firmware a couple of weeks ago having not upgraded for a very long time before that.


There is no doubt in my mind the ANC problems I'm now experiencing are linked 100% to the firmware upgrade.  I've had the headphones since 2018 and the ANC has been fine until this update.


I'm pretty disgusted by Bose - they have no interest in helping because it's out with the two year Warranty period.  Their only solution was to offer to sell me a new pair at a "discount".  The discounted price is considerably more than the current cost of the headphones with independent retailers.


All I want is to be able to downgrade the firmware.  It's outrageous Bose don't allow me to do so since my problems are as a result of their software update.  It's fair to say this experience has probably killed off any chance of me buying Bose products in the future.

Sorry to hear that you upgraded your headphones, Bose some time allowed to downgrade but even this will not help at most of the headphones, users believe that upgrade messes with chip thats why it doesnt help , Bose made tests of course everything looks perfect on their side, ı dont even use my headphones anymore and  doesn't feel like selling them as that wont be fair to others.


I just create an account to report the same issue about DRASTICALLY changing on ANC level. My problem that I bought it in UK and how to change QC in this pandemic time and living in Brazil? How to downgrade from previous version? This is a disaster! This issue is happening more than year and Bose not giving any option to customers! I am furious! Totally regret to not bought the B&O or Senheiser option!