I have a windows tablet that uses Intel drivers (generic?) for audio, and whilst the built in speakers' volume is fine, the volume outputted via the headphone jack is quite low. I have tried heard that disabling sound enhancements can help, but I have no such option.
The closest thing I have is something called "system effects" 
I have tried both disabling and enabling system effects to no avail.
I have also tried updating the drivers, but the newest versions are installed apparently.
In 'Levels' I have got the volume on full and the left and right channels on 100.
Any ideas?
EDIT: Here is what the volume mixer looks like:
Best Answer
Maybe your computer thinks you are currently "communicating" for some reasons:
Try to select the "Do nothing" here. Does that fix the issue?