Do they pop when there is no sounds being played?
If yes, then most likely you have an issue somewhere.
Possible issues, could be a number of things.
-Poor power quality. Add a Battery backup to the whole computer this usually works. It also can remove annoying buzz and hiss.
-Static discharge from you or a fan in your PC. To solve this you need to make sure your case is grounded to the PSU. If everything looks good then you most likely have a loose ground in the wall outlet. I do not recommend opening it. But if you are set on being an electrician follow my lead. First find your breaker box usually in your garage or outside at the side of your house. If you live in an apartment it coudl be in the water heater closet or in the kitchen. To fix the ground shut off the breaker to your room. To do this I recommend you turn of your computer and plug in a light in that socket. Turn the light on and go switch the breakers one by one untill you turn it off. Then you are safe to move in. I bet you are looking for a Flashlight now aren't you
. Ok now in the outlets box there is going to be three wires, White, black, and Green. You want to make sure the green has good contact with the metal power box. If the box is plastic look for a grounding screw in it. If there are no grounding screws in it your out of luck as i will not advise you to rip apart your drywall just to ground your PC
If they only pop while music is playing I would still suggest the above but i would also advise you to try another sound source to see if it is just the speakers amp. Take a portable music playing device. It can be a MP3 player a tape player, whatever you got. Plug the speakers input cable into the device and listen for the pops. If they are still there then your speakers are the culprit. If not then the problem lies somewhere between the soundcard and the wall. Good luck with it as trouble shooting audio in a computer is a pain.
Let me know if you need any help