Now I don’t know if it was just a sign from above that I need to clean and tidy my computer area more, but yesterday I received a pleasant surprise for doing just that!! My rear center speaker started working again. It hasn’t emitted so much as a pop since I used a heavy duty electric staple gun to attach/implant the wires cleanly to the ceiling! It seemed quite clear at the time what the issue was and since then, I have been on the verge of taking it down and throwing it away a number of times if I could have been bothered to remove the staples! It is not clear exactly what I did when cleaning to actually solve this problem, but it now works perfectly! It was either the static held in the dust or alternatively, perhaps I just pushed a connection home that was previously loose. The latter seems more likely but very coincidental timing that it stopped and started working at these times.