Interesting, there must have been a change up in the design of the cross over . The picture I posted is a v2 M80 . It appears your crossover is attached to the terminal cup.? Without any obvious signs of leakage and since I doubt you have any equipment for testing the capacitors or resistors I would say either send that crossover in for diagnosis or see if they will sell you a replacement.
Since you bought these from a friend, I would assume you have listened to music at his place in the past, did this noise ever present itself before?
Edited by Socketman (02/13/13 03:40 PM)
DOG is GOD spelled backwards.
I blame my terseness on my keyboard.