Certainly use the original boxes and packing foam from when they were shipped to you so they don't move inside the box. I recently shipped a tube amp and an integrated SS amp and I double boxed but the outside box was big enough that I could add 1 1/2" of styrofoam (sheet roofing insulation) between inner and outer boxes. Both made the journey safely. I don't think it matters if the RAAL tweeter is vertical or horizontal. My Ottavo came crated with the speakers on their back.
