hi all. today i received a fender RI sunn 215 rated at eight ohms i want to run it with my other cab, a vintage randall r610s rated at 5 ohms. as far as impedance is concerned i read somewhere that cabs with an odd impedance i.e. 5 or 6 ohms you should just run these cabs one step higher i.e. 5 ohms=8 0hms is there any truth to this? i will be running a beta lead which is a 4 ohm load and im figuring that these 2 cabs would work fine in this setup however i also have a sneaking suspicion this will drive my head too hard help me!!!