My Logitech Z506 speakers are producing something like a popping noise (like the one when you are unplugging or plugging a speaker in). It happens whenever my subwoofer plays a significant note. If the sound is enough to vibrate the top of my sub, then the popping sound is made.
I've made sure all of the ports are plugged securely.
EDIT (Less than 5 minutes later) :
I decided to unplug everything and blow out any dust in the way, then plug it all back in. That seems to have done the trick. I promise I'm not usually impatient enough to not try the most basic things first