Bose QC 35 ii firmware 4.5.2

Friendly Fanatic

Re: Firmware 4.5.2 QC35 ii

Hi Ikozz,

I have just resetted it but it has no effect.

The thing is, I clearly hear white noise when high on ANC.

The white noise replaced the muffled cabin pressure..

I have model QC35-II, and AZ...


Wistful Whiz

Re: Firmware 4.5.2 QC35 ii


>After all these weeks and still no solution to this problem from Bose.

>Ive found the SOLUTION!!!

>Sell it, give it to someone or return them.

You have been here for a while and know that:

1. Bose is still looking for a 'cause'.  In fact, we can not say ourselves what the cause is yet.  We all agree on the 'symptoms'.  We are disappointed (and there are those who are angry), that Bose has not even acknowledged the symptoms.  However, I believe as they are company and we are the customers - that we can separate out the symptoms from the cause.  Bose will probably not officially admit to the 'symptoms' until they determine the cause.  I personally OK with that since they at least for the last month or so, now regularly checkin here.  They don't necessary say anything 'meaningful' but for them omho, just posting here regularly is a big step.

2. As I have mentioned here the last few days, as we can't say ourselves what the cause is yet, it may not be with the firmware itself (as Bose suggests) - it could be with the upgrade process or even with Bose Connect.  When I upgraded to Bose Connect 9.0, and I started it but made no changes to any values (just opened the setting screen/display), it seem to me the ANC changed.  We know for sure that the Connect app does have code in it which will impact the ANC since you can set the action button to ANC (Noise Cancellation).

3. We as customers want to think in days and weeks.  Bose thinks in months.  We may not like that, but by now we have no reason to expect anything else.  There are quite a few things that impact the QC35ii - the firmware, the upgrade process and the Connect apps and the IOS versions may not be the same as the Android versions (which could be different from the downloading on mac and windows).  Point is, one or many of the 'contributors' could be involved in the cause and once the cause(s) are determined the time required to apply and deliver a 'fix' varies by product and fix which again could be in months.  It took Bose over a year of 'testing' before they admitted in this forum that the QC35i on/off problem was caused by hardware.  We found the cause much quicker.  I have been reading here for months about the 'symptoms' and many of made suggestions what the cause(s) is/are, but to be honest even we don't have conclusions yet as to the cause.  Without a cause there is no fix.

4. As customers we purchase and we can give away / return.  Certainly our perogative.  Perhaps Sony fits someone's need more - perhaps another competitor.  Thing is, doing that will not solve anything - it merely removes us from the situation.  For those who want or 'expect' immediate or quick fixes, we are mostly in agreement here - getting a Bose product may not be the right solution.  Things with Bose move much slower and in some cases (like my Revolve refusing to connect to an outgoing phone call from my iPhone 7+) - there is no fix (or it's 'expected behavior' such as our concerns with the BLE implementation with the Revolve).

I for one, have a pretty good idea of what type of 'ride' I am in for.  In most cases, my Bose products do what I expect even when they have quirks and issues and things I am unhappy about.  For my own personal work environment (which includes a music creation studio and airline flying), the QC35ii plays the music fine, allows me to talk on my iphone (much more effectively than my Revolve) without people saying I'm cutting out, and gives me ANC on HIGH that works for me (even if there may be an issue with LOW).  For me, the HIGH still sounds HIGH and not sounds like a LOW.


Audible Advocate

Re: Firmware 4.5.2 QC35 ii

How do you downgrade the firmware?

Wistful Whiz

Re: Firmware 4.5.2 QC35 ii



>How do you downgrade the firmware?

Downgrading is not recommended or supported (whatever that means) by Bose.  With that in mind, do a google search on Reddit.

Friendly Fanatic

Re: Firmware 4.5.2 QC35 ii

A video of testing the blBose Nc700 vs Qc35II with 4.5.2 vs QC35II with 4.1.3:

Get Them Here: Sony 1000XM3: Bose NC 700: Bose QC35 II: Visit My Amazon Storefront For My Top Rated Products 🐐: Sign Up For A Free Trial Of Amazon Prime There's a ...
Friendly Fanatic

Re: Firmware 4.5.2 QC35 ii

Bose, where is the cabin pressure on my QC35II's Firmware 4.5.2?

Please drop the nightmare 700's and concentrate on fixing the above for your current user base..


Get Them Here: Sony 1000XM3: Bose NC 700: Bose QC35 II: Visit My Amazon Storefront For My Top Rated Products 🐐: Sign Up For A Free Trial Of Amazon Prime There's a ...
Friendly Fanatic

Re: Firmware 4.5.2 QC35 ii

Hi guys,

One final update from my end.

Because I think i'm going mental..


I'm now again on update 4.5.2. AZ version and updated via the new Bose connect app 9.0..

The ANC high and low is still of sub quality compared to earlier firmware but even more important, the white noise has increased dramatically.

In fact, when I i'm in a somewhat silent room and shut down the headphone,

the white noise in ANC mode is making more white noise then without ANC, haha.


Here's what happened so far:

- Returned my beloved headphone QC35-II after 4.5.2 update over the app (pre 9.0).. ANC quality dramatically degraded.

- Received a new headphone from Bose QC35-II, fabrication date June 2019..

- It came with firmware 4.1.3. ANC quality was not good compared to the returned headphone.

- Downgraded to 3.1.4. which the ANC was slightly better.

- Updated the Bose connect App V9 today as I thought Bose had fixed the issue, so updated to 4.5.2.

- Then had to also update via the computer with message Bose connect app can't update voice commands?

- So end status... the ANC quality is still shiity, there is no cabin pressure and the white noise in ANC mode is very obvient..



Friendly Fanatic

Re: Firmware 4.5.2 QC35 ii

Dear God and dear Bose,


(Im feeling your pain Hendrik)

This is too painful to read as more and more suffering this ANC fanatic insane issue, I think Im going mental with Bose products too. Been a big fan for many years but after this fiasco, Im aiming towards Sony and JBL now for my next product. I walked by the Bose shop last week and got an illed feeling thinking about owning another product and going crazy if it acts up like the QC35ii now. 

Audible Advocate

Re: Firmware 4.5.2 QC35 ii

I bought my QC35ii at the Hong Kong Airport a few months ago.

I opened the box inside the plane for my long 10 hr journey to Doha.

I thought it was weird that I could hear the engine noise a lot more than previous headsets I've owned in the past.

Then I found myself looking for answers until I came here.


So today, in a leap of faith, I did the following:

1) Downloaded the 9.0 Bose Connect App and let the firmware update to the latest 4.5.2 hoping it'd be better

2) Prayed 

3) Waited



The High and Low are identical!

No significant change to the ANC

I can hear the clock ticking in the background and some other ambient noise that weren't there before


I am sad. 


Quiet Contributor

Re: Firmware 4.5.2 QC35 ii

I agree, they need a MAX isolation mode on top of high / low / off