Quoted from Jeff_PHX_AZ:
So you all running 4 ohms in the panel/backbox and the cab. speaker is 4 ohms. Now the old cab. speaker I pulled out was rated at 8 ohms, what gives?
Sounds like someone replaced it before you got it, maybe? If I remember right, I did research and listened to the guys here for the ohms, because my T2 has 8 ohms, so I had to order different speakers for each pin.