After speaking with JC on the phone and after swapping out drivers between the two 80s and with one of my M60s the issue is a bad driver ... EZPZ.
Whenever I did the swap, only one driver from each speaker was swapped to determine whether or not the issue followed the driver or stayed with the speaker and while doing so I found a tear in the top woofer of the good M80 so I ordered a pair of new drivers.
Here's a photo of the torn driver I found the from the 'good' M80 whenever I was doing the swap, it's a pretty good tear but the driver seems to be working just fine but I'm replacing it anyway.
I should have listened to Rick (Wid) from jumpstreet last night and did a driver swap then.
