You should already be able to use your speakers if your motherboard has any sound output. The extra control is provided by software, and though a sound card's drivers should provide you with control over the sound of all applications it would be cheaper for you to just use the built-in EQ in windows media player, for example.
Windows media player only has volume. My computer speakers are quite good quality. I want a semi pro type set up ware I can adjust more then simple volume like a eq program?
My audio system for the home retails for about the same as a new mid range sports car, so im not expecting miracles.