First off all download Volume Boost 3.0
Extract the zip file to somewhere on your desktop
SSH into your iPhone
(SSH is a service that you can install and run on the iPhone that allows you to access the phone's files / folders from your PC or Mac)
Goto this folder:
"/System/Library/PrivateFramework/Celestial.framework/folder"
Find this file
"RegionalVolumeLimits.plist"
and rename it to
"RegionalVolumeLimits.bak"
Copy over the RegionalVolumeLimits.plist file that you extracted earlier to the iPhone's /System/Library/PrivateFramework/Celestial.framework folder
Set permissions to the RegionalVolumeLimits.plist to 0777
Reboot - Job Done
You should now notice a difference in the volume, though you may want to change your equalizer settings so its not distorted.
Volume Boost 3.0
