Apple 5S phone with thin current sound what's going on

Reason Status

Why is my new 5S call old with thin current sound? What's the problem? Just bought the machine, the system has been upgraded to ios7.0.3.

Solutions

There are many reasons for this problem:
First, the surrounding magnetic field radiation is large or the network signal is not very good, this situation will occur.
Second, it is possible that the motherboard audio control IC problems, it is recommended that you go to Apple repair shop for testing and maintenance.
Third, the delivery device has problems, find maintenance personnel to help you change a transmitter can be resolved.
Four, you can try to click Settings-Wallpaper and brightness-adjust the screen brightness to the maximum, see whether there will be, brightness adjustment to the middle or any darker brightness to try whether there is.