What do you mean something doesn't feel right?
When I use my cheap *** $20 Sony headphones via the front panel headphone connector, the sounds and music sound like they have full range. When I use the backpanel connector, the bass disappears. However, I found out that changing the setting in the audio connector software from headphone to line out made a huge difference in sound.
Try that, if your software does that, and let me know if that's what you're looking for. To be honest, you didn't really explain what is wrong.