Dell Dock State D3100: How to turn of main speakers when headphone are plugged in?

[nhatpham]

I'm not sure if this is how the system works. But I would expected sound would switch and output to headphone only when a headphone is plugged in to the dock station. However, I'm not sure why but the dock station output to both headphone and speakers. I'm sure if this a configuration on my pc or something is not working properly with the dock station. Please advance if some have experienced this issue and was able to resolved it.

Thanks

[AlbanRampon]

Hello,
As far as I know, the behaviour you describe is how Dell has made their docking station to work.
This is not something you can change as it is hard wired.
Kind regards,
Alban