Please disconnect the Teufel speaker system from your PC or other connected devices by unplugging the cable and check whether the “crackling” stops. Try operating the set with a different power source/in a different room (just use an extension cable).
If you can still hear the crackling, please check which satellites are affected by swapping them around and to find out whether the satellite or the subwoofer electronics are generating the excessive crackling. If the "fault" moves with the satellites, the satellite is affected. The subwoofer amplifier electronics may be responsible if you can still hear the crackling.