Not sure of size of the brand of speakers you are talking about! If they would fit in a hard shell suit case that is not bigger than what is allowed for a carry on. I would do that or i would pack them very very well and ship them. TSA may inspect them in front of you as a carry on, but it should not be a problem. Checking them is dangerous-There is no TLC applied to unloading and loading checked bags. Not to mention they could disappear.
Good Luck