I've had a lot of in-ears and put them through the daily call + also for the music in much. These headphones have disappointed me from the beginning, because of the lack of bass / depth and from the beginning have me many callers do not understand - this may simply be due to an unfavorable microphone alignment by Sennheiser at least I did not have these problems with the UE 900 or other products , After exactly 6 months + 1 week, the plug connections and terminals are now broken to the monitors and Amazon do not want to take back the things. So buy anew.
