My iPhone 6 Plus, purchased on 12-18-14, and my wife's iPhone 6, purchased 9-19-14, both have had really low earpiece volume. They were like this from the very first minute they were turned on when new; just out of the box. We have put up with this all this time. We've tried every suggestion that came our way. But basically, unless you were in a quiet room, it was very hard to hear the person calling. Well, I finally contacted support yesterday and had them set me an appointment with the Genius Bar. After checking in, the guy helping us made a test call with my 6 Plus. He commented that the volume was indeed really low. He ran through all the routine checks and said they would replace the display. He then did the same with my wife's 6. After the test call, he said hers was even worse. 2 hours later we came back to the Apple store to get our phones. Checked them over to make sure they still looked new.....they did. My wife called me and when she spoke it was so loud that it actually shocked me. And hers was the same. My daughter called because she was trying to locate us. ( Apple store is 50 miles away from home. ) I answered the call and when she spoke, I had to quickly pull the phone away from my head because it was so loud. On Monday, I am going to see what the volume is like on some of the other iPhone 6 owners in my workplace. So, the moral is, if you are having this issue, get to an Apple store. There is a fix. I do wonder if Apple is/was aware of this and has updated parts out there to fix it for those that complain. I was a pretty happy 6 Plus user. Now I am completely thrilled with it.