Signal cable arcing to speaker
In my building we have a few powered speakers that are daisy chained together signal-wise. These speakers are exhibiting a huge amount of hum and noise when they are not receiving a signal. I pulled one down earlier today to do some testing. When I went to put it back into place, I had no signal running and the signal cable to the first speaker in line had actually been removed, the xlr cable's connector arced really badly to the xlr jack/speaker chasis. The speaker was turned off, but did have the power plugged in. Assuming that any damage was already done, I unplugged the power cable and then tried to plug the jack again and got no arc. Any ideas as to what's going on here?