ANC Deterioration on Bose QC35's

[shehanw05]

So I bought some QC35's second hand around 5 years ago. The ear cushions were pretty worn (so got a good deal), but the rest of the headphones seemed to be in really good condition.

I have been really happy with them in terms of sound quality, and battery life. They were also my first headphones with active noise cancelling, and was pretty impressed with how they attenuated background sound. However, I then bought some Jabra Elite 7's, and was shocked how I could notice such a big difference between ANC on and off - I wouldn't really notice a big difference on my QC35's with ANC on/off. Therefore, it has made me feel like most of the noise cancelling effect I have is just passive.

Furthermore, I tried some QC Ultra's in store, and while I understand they are better headphones than mine, I was completely blown away with the ANC quality. However, when you compare the measured ANC performance between the Ultras and the QC35's in reviews, there isn't a significant difference.

This has lead me to wonder if the ANC on my headphones isn't working as it should. A few theories I had:

1. Not using official ear cushions. I bought the Wicked ones from Amazon, which have been comfy, but wonder if they were affecting the ANC algorithm tuning?

2. Microphones dirty/blocked? Based on how I understand ANC works, I could imagine this would limit how well the ANC can perform. However, I use them for calls and never have any complaints about mic quality, but I do believe different microphones are used for calls and ANC.

3. Not getting a proper seal with my ears. I do have fairly large ears, and after extended usage do get sore ears from the ear cushions sitting on the outside parts of my ears, so wonder if this limits the effectiveness of the ANC. Worth noting, that I have never experienced an uncomfortable pressure some people experience with ANC headphones.

Too be honest, this doesn't take away that much from my enjoyment of the headphones, as I just love the sound quality. However, it would be great if there could be a simple fix/change that would allow them to perform at their best. I'm also just very interested in how ANC works, and definitely understand it very well, so any deeper insights would be much appreciated!

 

[Drengur]

I've had a few of those Q35s. I use them ALOT and I am not very kind to them. The ANC working well depends on everything being in tip-top shape. All of these issues you mentioned are possible. I have to change the pads every 12 months or so. As well as the cloth inside. You should also clean them out regularly (if you are as bad as I am with using them when you are doing home improvement and working in the garden). They can gather a lot of dirt on the inside and the Microphone can easily get clogged as well with sawdust and such. The electronics inside are not very fond of water and I've managed to destroy a pair by being stupid,

Tl;dr. Changing the pads is a must as they get squishy and deformed, which causes bad sealing which causes bad ANC. It's cheap and easy. I would try that first. A software reset is also sometimes needed. I've had mine drift out of spec for some reason, causing static sound - which was fixed by a firmware update (not for fixing this, but it resets it somehow).

 

[shehanw05]

I've had a few of those Q35s. I use them ALOT and I am not very kind to them. The ANC working well depends on everything being in tip-top shape. All of these issues you mentioned are possible. I have to change the pads every 12 months or so. As well as the cloth inside. You should also clean them out regularly (if you are as bad as I am with using them when you are doing home improvement and working in the garden). They can gather a lot of dirt on the inside and the Microphone can easily get clogged as well with sawdust and such. The electronics inside are not very fond of water and I've managed to destroy a pair by being stupid,

Tl;dr. Changing the pads is a must as they get squishy and deformed, which causes bad sealing which causes bad ANC. It's cheap and easy. I would try that first. A software reset is also sometimes needed. I've had mine drift out of spec for some reason, causing static sound - which was fixed by a firmware update (not for fixing this, but it resets it somehow).

Ok thanks for the reply. With regards to changing the cushions, have you noticed a difference in ANC quality between different cushion brands. I've currently got third party cushions which have lasted well and are comfy, but wonder if sound/ANC performance would be better with the genuine cushions.

Also, regarding cleaning the microphones, where would you say the most important parts of the headphone are to clean from your experience? I would say I do treat mine quite carefully, so they don't get very dusty and I can't see much dirt behind the cloth inside. I would believe that the holes on the outside are for the microphones too, but I wouldn't say they look visually clogged, but maybe I should try to take off the plastic cover to clean them more thoroughly?

 

[Pareto Pragmatic]

but maybe I should try to take off the plastic cover to clean them more thoroughly?

I'd start with compressed air, see if that helps. I'd rather start with that and take things apart if needed as a second step.

For the seal, try pressing the cups onto your head (making sure not to cover the mics). That should improve the seal and give you an idea if this is a major factor or not.

 

[voodooless]

https://www.reddit.com/r/bose/comments/e70kvr/headphones_qc_35_ii_with_a_downgraded_anc_because

Bose never confirmed this was happening, though

 

[Drengur]

I've never tried 3rd party pads. I am lucky in that I was provided with replacements at work. New pads improve the ANC quite a bit each time. I had also not seen issues regarding firmware breaking ANC. I would never believe firmware was used to force people to buy new stuff! /s

 

[Feelas]

I've never tried 3rd party pads. I am lucky in that I was provided with replacements at work. New pads improve the ANC quite a bit each time. I had also not seen issues regarding firmware breaking ANC. I would never believe firmware was used to force people to buy new stuff! /s

This supposed FW issue is not reproducible by many, so that'd either be a bug or somehow limited probability to not break all of them at once.

 

[shehanw05]

Ok thank you for the information guys. I have ordered some genuine earcups (needed some new ones anyway), and will get give all the mics a good clean-out with some compressed air. I am also very interested to try pushing the headphones to test the quallity of the seal.

I'll update this thread after these updates

 

[DonH56]

Ok thank you for the information guys. I have ordered some genuine earcups (needed some new ones anyway), and will get give all the mics a good clean-out with some compressed air. I am also very interested to try pushing the headphones to test the quallity of the seal.

I'll update this thread after these updates

Blasting microphones with compressed air is usually very bad for them. The high-pressure air stream can rupture the membrane. Same thing can happen using a a vacuum. A soft fine-hair brush used very gently is the usual method if anything. Some diaphragms can take more abuse, but I'd be careful cleaning them. The only time I recall fiddling with noise-cancelling headphones, I disassembled them (a PITA), and cleaned the openings in the housing, but did not touch the microphones themselves. In that case dirt was blocking the openings but had not been caked onto the microphones best I could tell.