I treat my cabs very differently than I do my guitars. My Aguilar and Acme ratfur cabs have been living in my truck camper shell outdoors for many years with no ill effects that I can discern. (Pretty moderate climate here - some triple digits in the summers but I think the white camper shell keeps things from getting too out of hand. It doesn't usually get very far below freezing in the winter.) Ironically the only woofer I've ever had to replace due to "rot" thus far was on my G/K practice amp that lives inside with all the instruments.