Einstein speaker jacks

from the user's manual: "Einstein has 5 speaker jacks. 1 for a 16Ohm load, 2 for 2 16Ohm loads or 1 8Ohm load, and 2 for 2 8 Ohm loads or 1 4 Ohm load. Confusing? Oh yes! Just do what it says on the jacks, and you’ll be fine"

I have been running 8ohm jack on Diezel into the 8ohm jack on my cab. Is that wrong? Seems like i need to run a single 16ohm jack on Diezel to 8ohm on the cab?

You are doing it right. A single 8 Ohm cab needs to be connected to one of that 8 Ohm jacks. If you had two 8 Ohm cabs, each of those would need to be connected to a 4 Ohm jack. It's Ohm's law

If you have two resistances parallel the resulting overall resistance is calculated by 1/R=1/R1+1/R2. So for both resistances being the same the overall resistance is just half the value of the single resistances.