Android - Stereo to Mono Sound
On Android 4.4:
- From your homescreen, hit the Menu key and open System Settings
- Go to Accessibility, tap cancel on "need a screen reader" to bypass / scroll down to "Mono Audio"
- Uncheck box
Done!
In S4, go to Settings > My device > Accessibility > Hearing
. You will find the Mono audio option there.
EDIT: You can download Boeffla Sound Control from play store. This app is able to convert Stereo sound to Mono. For this you must first install Busybox which is also available on play store. Your devices needs to be rooted. Hope this solves your issue.