Re: Firmware 4.5.2 QC35 ii
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.