I took shipment of 3.6 from the factory, years ago. In addition to the cardboard box, they used metal straps to attach it to a customer-sized pallet and sent it special freight. This shipment was to remedy the original 3.6 that someone shipped to me in just the original boxes. They were d-e-s-t-r-o-y-e-d.
DO NOT EVEN THINK of shipping this speaker even next door without some sort of pallet. You achieve the same results much quicker by standing at the window and throwing money out of it. Flushing down toilet also works.