welly321

Hi All, I have a Klipsch Pro Media 2.1 system for my computer and I've noticed my sub makes a strange rattle noise at medium to high volume. The sound doesn't appear at low volume. Here is the video with the sound.... https://www.youtube.com/watch?v=LANk2NqgY9M Does anyone have any idea what this is or how to fix it? Is this normal? Its only noticeable in normal use if I turn the volume up.