I recently bought a Plantronics Voyager Legend headset to use with my Samsung Galaxy Note II phone. It worked fine for a day or two, then I started to experience poor sound quality. Especially the person I was talking to had real trouble hearing me. Restarting bluetooth in the Samsung or restarting the Plantronics headset did not help. But restarting the Samsung Galaxy Note II resolved the problem momentarily – after a day or two the problem returned.
Before returning the headset to the dealer I decided to have a look at Plantronics website and found out there are a firmware update procedure availible on their website. To get the update software running on my Windows 8 PC I had to run the installer as administrator. When returning to the update window in the browser (yes, the update procedure is done all in the browser), I found my headset was running firmware version 44 and an update would update it to version 93.
After updating the firmware all quality issues where gone.
To update the Plantronics headset visit http://www.plantronics.com/us/support/myheadset/updater/