Cons: Low sound quality ; noisy noise canceling mode
I spend so many hours reading your reviews that when I saw there wasn't any for the Bose QuietComfort 20i NC, I decided to write my first review ever.
So please be kind with me, I'm not a pro (and not a native neither) ;-)
You have to know...
...I'm not a huge fan of Bose products. I tend to find them expensive and not great sounding at all, with fake and disturbing bass and really unpredictable highs.
I never liked in ear headphones. Somehow, they never fit my ears and after 5 or 10 minutes I've always felt the need to remove the ones I wore. I'm not talking about this awful cable noise... Well, this was before I tested the Quiet comfort 20. Those are the most comfortable in ear I wore so far. It's probably due to their very clever sleeves made of soft silicon : they got a small extension that seals them in your ear but not profoundly at all. The result is I can wear them for hours and especially when I try to find sleep. Of course it never will be as comfortable as over the ears cans for me but hey : 9/10.
Noise canceling mode OFF : awful sound. Very muddy, no soundstage at all : the QC20 are clearly made to be listened to with noise canceling mode ON : 0/10.
Noise canceling mode ON : much better. For a Bose product, the bass doesn't sound fake and its extension is slightly better than average. The mids sound very flat to my hear and I had no fun at all listening to this particular frequencies. Highs are not so badly controled : of course, you won't have the precision you can have with the Audio Technica AD 900X for example, but it's not so bad. Regarding the sound quality, the main problem comes from the huge lack of details and soundstage : 5/10.
= the reason you want to buy those very expensive iem. Well... Sure, it works, especially with the low frequencies (you can still hear voices and metallic sounds, for example). But the craziest thing is the noise canceling mode produces ...noise by itself ! It's not huge, but you'll sure hear it when the music is not ON and once you've noticed it, it's very disturbing : 4/10.
Conclusion = 4.5/10
Really disappointing iem. Neither the sound quality and the noise canceling are satisfying and I'm sure you don't want to buy iem only for their comfort ;-). I'm still waiting for the next improvements though because somehow if the noise produced by the noise canceling mode disapeared, and if the sound quality was slightly improved, especially in the mids, well, the QC20 would be a nice pick.
Hope this review could be useful to some of you.