If you want to insure proper handling for anything larger than monitors or subs, or ANY electronics, don't use ground shipping from anybody! Use a reputable airfreight company (even FedEx.)
For example, I shipped a pair of ARC M300 MkII tube amps (2- 2x2x2 foot double walled original ARC boxes, 120# ea.) by FedEx "Express Saver" (3-day airfreight) from Tucson to Dallas, including $6000 insurance, for a little over $330. FedEx Ground would have been $260. So what's the big deal!? They arrived promptly, not a scratch or dent, and FedEx overnighted the COD cashiers check they collected back to me for another $4.50
Most buyers have no problem spending an additional 5 - 10 percent of the value of their purchase for the best and fastest air shipping. And, if there ever is a problem, airfreight claims seem to get resolved with less hassle.
Another tip (even with airfreight) is: use crates and/or pallets whenever possible, even with small stuff. And ALWAYS use them whenever sending two of something (speakers). Again, the additional cost is negligable, and it automatically requires more careful handling and less stacking.
Otherwise, avoid ground shipping unless the item is very cheap, or very indestructable (like a big isolation transformer or something.)