These head phones work great. These other reviews are complaining about the low power Bluetooth signal. This has nothing to do with Sony, it's your crappy cell phones.These really sound good, in contrast to some other reviewers, i find the bass very good. You also might need to adjust the setting on the music output, i.e. your phones mp3 player to adjust the treble and bass.I really love these bad boys, and they work for over 6 hours before I have to charge them. The trick is finding the hidden on/off button, as they do not turn off by them self.Also, the phone feature works great. All the people I've talked to on the other end say the voice quality is great.