I think a 4 x 10" cab would be ok.... Otherwise two 2x 12" cabs.... Thats what I would use... The "percieved advice" is that 10" speakers are better than 12" speakers for harps... I just don't know.... I have always favoured 12" speakers....You have a mighty amp there, I'd love to try it out... ENJOY! Best wishes John Walden London England