sladehk said:
i think its because when the speakers start, they make the sound and when you turn the speakers off they also make a pop sound too
As already mentioned the hissing noise comes from static or interference and can't gotten rid off completely unless you throw in the money for better speakers, shielded cables and a better sound card. If the hissing is noticable even at "normal" volumes you might want to consider rearranging your current speaker set up, such as not having any speaker signal cables parallel to any power cables.
The "pop" sound is a sound made by suddenly applying power to the speakers, ie, when you turn it on. Circuits try to minimise this by having a high capacitance capacitor parallel to the speaker to absorb the spike, and is not related to the background hiss.
blackbunny said:
when i get my headphones and hook it up to my leet pc they dont make any noise .
The hiss is still there, but either it is outside of the headphones dynamic range or the headphones is not as loud as the speakers so you can't hear it.