2.7 ohm load with a 2 or 4 ohm amp

ok so this isn't wariwck related persay, but ive been posting alot on the talk bass forum lately so i thought id come here.

heres the deal, im planning on getting a new head (not to be named, lol )wich has a switch that allows it to run a 4 or 2 ohms.

the cab that i want runs at 4 ohms, and i really like this cab, and want to use it.

but i would also like to add a second cab a 1x15 which is 8 ohms. so this is a 2.7 ohm load,

now my question is how many ohms should the head be running the four ohm position, or the 2, common sense would tell me 2 but would running a 2.7 ohm load in the 2 ohm position harm it? and the head is an all tube head if that means anything,

thanks

 

Hey Andy,if you run both cabs select the 2 ohm switch.