Sep 22, 2019
My AZ series, 2019.03 qc35 ii headphone was come with 4.1.3.
I was hear about the broken firmware thing before I bought the headphone, so not updated to 4.5.2. For safe, I never tried 4.3.6 and 4.5.2, becouse some people report permanently bricked headphones.
But I tried 2.1.3, 2.2.1, 2.5.1, 3.1.8, 4.1.3.
All the same sound quality and ANC!
So I use the 4.1.3. There is difference between low and high and it has the cabin pressure.
I tested one firmware one day at work and on the bus. All is the same from 2.1.3 to 4.1.3.
Unfortunately, with my AZ series model, i can't downgrade to 2.0.1 Every time I try, the process fail at 76% (sqif partition write or erase error). I tried with two different PC's.
I think anc headphones only cancel low frequency noises. I can hear people talking clearly with the bose and even with the sony wh1000xm3.
So far I dont have any problems with Bluetooth with my iPhone and laptop (Windows 10) connected at the same time. The connection is stable and the sound quality is good.
There is no white noise when the ANC high enabled. It is deadsilent when no music is playing 🙂
When I am sitting in the garden while it is a little windy I hear the wind with anc on high. When I switch to low mode the wind noise is gone.
If I was you I would try the downgrade to 2.5.1 You can always go back to newer versions!
btw are you the famous Olaf Mol from Ziggo sport Formula1? haha 😄
sounds good! Do you have an AZ or AE model?
(NB no ziggo F1 relation 😉 )
I have an AZ model. Updating works fine, I tested almost all versions 🙂
tnx. It's intriguing how some people report no chances in ANC performance between different firmware versions, while others definitely hear big differences.
Myself, i'm on firmware 4.1.3 (factory firmware version), with an AZ model. I do hear the ANC working, i do hear a difference in HIGH and LOW and OFF, i also hear white-noise with ANC enabled, and i do also hear more incoming noise and sounds than I would have expected. Still on the fence if i'm going to try and downgrade or not. I'm ok with the current performance, but I'm also curious if an older 2.x firmware will have a much better performance than my 4.1.3. Hmmm, choices choices 😉
Sep 23, 2019
I signed today to share my thoughts.
Today i downgraded from 4.5.2 to 3.1.8 and i realy can't hear any difference. Same white noise, same ANC performance 😒
My headphones were shipped with 4.1.3. After i get it, the update to 4.5.2 came in. I have no experience with other firmware versions then 4.5.2 but i was dissapointed by the white noise.
Sep 23, 2019
I updated a month ago and after resetting ANC to Low and then High everything went well.
Today, I noticed that when I'm listening to audio from my laptop I'm hearing a ton of noise from the room, as if the ANC is off!
After a short investigation I found out that Windows has changed the audio device to QC35 Hands-Free AG Audio instead of QC35 Stereo. This means that when I was streaming audio via Bluetooth, Windows was treating QC35 as if it was a hands free microphone, and was turning on the mic, letting me hear the surrounding room.
I switched the audio device back to QC35 Stereo and disabled the hands free device, and voila - ANC is back to normal.
I'm not sure this is relevant for all of you, but this is definitely something you should check for.
Aug 8, 2019
If you do that is this the screen you get, just with 2.0.1 on the bottom stated version? http://prntscr.com/pb9cid
I followed @Heijmenberg's post and my ANC is restored (device s/n ********AE). I didn't downgrade to firmware 2.5.1 but the earliest version 2.0.1. The Bluetooth connection is stable and it works fine with my iPhone and MacBook Pro. Also, I tested the automatic switch-off function, it works fine as well. Hope this information can be helpful.
Can the people running on 2.5.1 let us know about the quality of the Bluetooth conmection, with single and dual pairing?
also interested in if there is any audible white noise with anc high enabled and no audio Playing?
last: does the anc low mode block out wind noises when biking or running?
Sep 26, 2019
Thank you, my headphones are back to life.
I have downgraded to version 2.5.1, and I am back on track.
I am working in a noise office, and I have noticed in the past months that I can hear all my environment, even my keytaps on the keyboard, and now after the downgrade, it is silent again.
I am so happy; it is fun to hear music again.
Its fascinating. A co-worker has purchased new QC35ii's (S/N with AZ) and these are running the latest 4.5.2 firmware (don't know if he updated or not, but i believe they came of factory with this firmware). I compared them to mine (running 4.1.3) and their performance was identical as far as we could detect. Difference between high and low ANC was clear, there was active ANC but still some voices coming through, acceptable to both of us. So it seems it might not be the firmware version itself, but the upgrading process from one firmware to another that might cause issues with the ANC?
Interestingly enough, this problem with firmware updates degrading ANC is already happening for 2 years, as you can read in this archived post from 2018: https://community.bose.com/t5/Headphones-Archive/Bose-QC-35-II-firmware-2-5-1-ANC-is-terrible/td-p/1...
Here the poster claims that an update to 2.5.1 severely degraded his ANC, and a downgrade to an earlier firmware didn't improve the ANC.
Intriguing to say the least. Any takers on what this could be? Some kind of neural network/calibration that is going on inside the headphones that breaks after an update?
For reference and comparison, I really like this video review, the guys records different surroundings with and without ANC, it's not clear which firmware version, but this is a October 2017 review, so it's probably some 2.x version. I must say the ANC effect he experiences is the same I have with my 4.1.3, is this also the "GOOD ANC" that you guys and girls are looking for, or having? Or is it worse than you would expect? Take a listen here: https://youtu.be/q8qMYKNutb4?t=352