I thought I was imagining this, at work when they have the radio on and I have my headphones on up full I can hear the still radio in the background, an issue I never had with my 5C, I always thought the 5C was a bit quiet at times as well. Today I hoaked out my old iPhone 4, there is definitely a difference in volume. The iPhone 6 only goes to a bout 75% volume of the iPhone 4. When the iPhone 4 is up full it is deafening. Has anyone else noticed this issue?