I recently bought a set of Logitech x-240 speakers. I like them, they sound great. However, from time to time (maybe every five to ten minutes), they make a "pock" sound. It's a sound similar to the one you get when plugging the 3.5mm jack on the powered computer while the sound system is powered on, altough it has less "attack". I have my volume set at about 70% (11 bars out of 16), so there shouldn't be any distortion caused by the computer digital-to-analog converter nor by the speaker amp. Any ideas?