Get the earphone after 2 weeks now return the following reasons (ranked in order of importance for me) again: 1) Cable Noise: Very loud noises, if you also move only his head slightly. The scraping noise that makes the cable on the collar or even the 3-day beard, tend to be stronger than normal in-ears. In this price range incomprehensible that has not been decoupled from here. 2) noise is too strong to mM, it's too much too clearly audible even with soft music. I have a comparison with the QC15, in this the noise is less. 3) rubber of the cable makes it on the clothes always "stick", handling, making it a bit annoying. 4) loud crack when you turn. 5) Long-term reliability is questionable, because the cable is not replaceable, see other similar reviews. 6) Underground sound when NC switched off, it is therefore useless.
All this must be seen against the backdrop of not just low price, hence my low rating. The very well-functioning Noise Cancelling (low frequency) is no question that it seems to me alone but to be too little, and as I said: The "deal breaker" for me are the annoying cable noise, everything else I would even endure. Except for the size of the QC15 thus clearly ahead for me compared to the QC20.