Practically all speakers at once?

When I bought this HHR (used), the only speakers really working were the two in the left front. The right tweeter makes some very scratchy sound; and none of the other three speakers emit any sound at all. I've shifted the sound from side to side and from front to back, and this is what I get, whether I'm listening to the radio or playing a CD. Is the problem more likely to be in all those speakers, or in the OEM radio?