short version: get better 3D sound placement in games via headphones in windows
some blessed maniac figured out a way to replicate the effects of a variety of high-end virtual surround technologies (Dolby Atmos, the various Creative techs, etc.) using a software EQ.
if it works for you this could be a great way to achieve precise sound placement in games without a dedicated soundcard or paid software. it is not without limitations but looks pretty robust (read thread)