Originally Posted by snookie
The iPhone does have better sound quality, especially during calls, than the S 4 but it sounds like his loudness issue is a defect of his particular handset.
My Galaxy S4 & iPhone 5 are on the same carrier, In my experience the noise cancellation system in my S4 is far superior to my iPhone 5. This is also confirmed by those I call.
In addition the clarity and range of volume adjustment is greater and more granular on the S4.
I'm not advocating for Samsung, but simply sharing my personal experience of each of these phones.