Agree with the above posters that I too would not consider shipping speakers unless you can take a hit. You have 100% responsibility that the speakers arrive undamaged, and will have to take them back and issue a refund to the buyer if damaged by the shipping company. Then try to recover through a damage claim. Unfortunately shipping damage happens all too often with large, heavy items.
With that said, if you must ship never use one of those packing/ shipping places. They are clueless and love to use those styrofoam peanuts. Buconero117 offers good advise for packing and I will add to that to only consider Freight, strapped to a pallet.
With that said, if you must ship never use one of those packing/ shipping places. They are clueless and love to use those styrofoam peanuts. Buconero117 offers good advise for packing and I will add to that to only consider Freight, strapped to a pallet.