rear speaker problem?

i had a bad crackle on my stereo a few weeks ago but after fading out the rear speakers it has gone, anyone know the cause? wires or the speakers them selves?

crackle could be any of those. Wires, blown speaker or knackered head unit. The standard rear speakers are awful and fitted to the plastic panel. Much better to mount some quality speakers to the inner metal skin.

new unit so ill try new speaker then, is there a guide i remember seeing on the old forum for remove rear door cards??