i am new here and i have tried to search the site but can not find anything. I am trying to figure out a way to hook up speakers to the rear dvd player instead of my kids using headphones. I have gone to walmart and bought a cheap kind (then an expensive kind) of speakers that use a usb for power. When the speakers are on the have a buzzing noise to them. Why is this? and more importantly what can i do to get the movie to play only in the rear?