I just wanted to know if it were possible to use an Egnater Renegade head with a Line 6 Spider IV cab seeing as it has the dual inputs (the cab)?
Yes it is. Doesn't matter which input you plug into.
Only if they are stereo inputs that split the cab into two halves. If it's just two parallel inputs you'd have to rewire it.
Alright, thank you guys! I didn't want to go out and buy this head only having to go buy a new cab as well shortly after.