ok I know what the problem is, do you have realtek audio by chance and the current drivers ?
If so, please open the orange speaker icon in your taskbar, and locate speaker configuration, put that on stereo 2.0 mode, and disable virtual surround if not already enabled.
Also please reattach your headphones to red jack on the monitor or computer speaker port.
Put the enviroment settings to parking lot, and equalizer to rock, not bass or it will be loud!
Set the volume level to atleast 35 or 40%, if that fixes that problem, atleast it will prevent you from getting locked out of the room or the place you live at.