I`m hearing a slight buzzing sound in back of my bookshelf speaker , mainly around the area of the binding posts. This is present when playing music with a boomy beat with a lot of bass like hip hop. Its definetely something to do with my binding posts. When i gently put my fingers on top of the posts they stop resonating and rattling. Can anyone tell me how to easily fix this? I tried tightening the plate but still no luck.