Max Volume sounds lower than usual ( Level 15 ) - Decibel Test
I would like to know your the decibels of your phone via the Audio Wizard play test music.
Mines sounds like its only level 10 and its weird.
I haven't done any decibel test for now.
But for testing via App I do recommend Sound Meter for testing and putting up the microphone of your other phone close to the Top Speaker and another test for the bottom one.
@Anders please help on this as it's another issue on the phone.
I've been playing Call of Duty at max volume with my co workers and they notice a big change on the sound level when we started to play.