So it seems like the front two channels (L&R) on my SC-816 are slowly fading out. The rears sound great, but there is definitely more volume coming from the rear than the front than there used to be (yes, I do have the fader set to the center). When I fade totally to the front, the sound is muddy and not as clear as it used to be. Anyone else experience this? Maybe time for a new headunit?