colterphoto1is absolutely correct - "fine furniture or antiques".
Now that said sometimes you do have to move things around - I just sent a 180 year old tea set in two boxes; each box was professionally packed by one of Englands finest professional china packers. Yes they really have professionals - not just some guy who can't keep a job and decided to open a "Pack-n-Mail".
I re-packed those boxes in two more boxes - each 24 x 24 x 36 - two boxes to send a teapot, 6 c/s, creamer, sugar and two serving plates - on the other hand there are only three known complete sets! so I figured a few extra dollars for packing is an INVESTMENT not a cost.
So first question....how much are they worth to you? NOT how much did you pay or get for them... but, how much are they worth to you?
If they are indeed "fine furniture or antiques" I suggest you pack them in the original cartons and then "wrap" them in 4-inches of polystryene foam sheets - NOT polystyrofoam, but POLYSTYRENE foam. 4-inches on each side - and there are 6 sides to any box - the bottom deserves as much protection as the top!
Next box them in a 350-lb burst-strength carton and palletize for shipment.....of course if I were sending my Beautiful Baby Belles back to Oklahoma the outer carton would be plywood and 2x4's with a carpet lining but then again I'm quite anal about shipping since my wife worked in the Post Office and I used to see the "back shipping dock" where the boys tried each package for "drop-kick" strength for amusement.
You can safely ship these speakers if you use a little common sense and spend a few bucks. "If you can't afford the shipping you probably can't really afford the goods inside...?"[:'(]