Just bought a new LG SJ3 soundbar with subwoofer. when i'm playing music, or just any kind of sound through it i can hear a scratchy noise. the soundbar has 4 membranes or speakers in the front, and the scratchy noise is coming from only one of them. If i gendly touch the speaker, pushing it a little in, the noise stops. any idea what this is, or if it is just broken. - Thanks