problem with the right JBL speaker

Hi, I have purchased a XPS L502x several days ago. Everything seemed to be fine unless a thing started to annoy me. The right speaker produces a sort of a "sh" lasting sound, I am not sure if it is correct to determine it as a static noise but that is what some people were referring to. With the volume up the sound of music or movies seems to be impeccable but in a silent room it irritates me(I hear that). One thing I noticed for sure, it starts to produce it when I click on My Computer, when I close the window it shuts down. It also produces noise when I start playing a media file even with headsets connected or when I mute the sound.

What is frustrating I have purchased it from dell.it (Italian site) and I live in a different country. Please let me know if I have to return it back for repair despite I really like the machine. I heard that might be sound board problem what causes replacement of the motherboard.