Speakerphone is plenty loud, don't use the mic jack for anything but bluetooth is fine..
my issue is the regular earpiece.
Even at MAX volume its far too low, literally if I'm not in a perfectly quiet room I cannot have a conversation without switching to speakerphone. And I don't really like the idea of having to use speaker phone constantly for every conversation.
My Fiancee recently switched from an iPhone to an S4, she has the same issue, cannot hear anyone except when using speakerphone.
Called ATT they said call samsung
Called samsung, they said they are "not aware of any issues with the in-call volume level of the Samsung Galaxy S4" and gave me an 800 # to call if I wanted to "voice any further concerns"
For all intensive purposes the phone is unusable except on speaker..
Ive tried Volume + and a few other apps, none really did anything..
What else can I try?