Just wondering about this since im totally new to head and cab set ups. Would there be any problem pairing a 100w head with a 2x12 cab given that the impedance matched up alright or would i end up blowing a speaker?
Mismatched impedance will damage your head's transformer. The only way you'd blow a speaker is if the wattage of the head is greater than what the load of the cab is. Your cab's manual should tell you its maximum load in watts and so long as this matches or exceeds your head's wattage, you're good to go.
Good luck with it!
Cheers Dave! Ive been offered a 100w head on the cheap and its a big brother of a 20w i was looking at. But i think 100 watts is way too much for me anyway.