The 3.7s are kind of difficult to get in the boxes, I've done it twice I think. They're only around 100 lbs, though. I replaced a pair of B&W N802s with the 3.7s and I almost killed myself getting the B&Ws up the basement stairs. My back was messed up for a couple of weeks. I had to get them around a corner and those stairs have a big lip so every stair was hard.
Now that I think about it I have a number of heavy speaker moving memories. I've moved my Velodyne dd18 a number of times and that thing is unpleasant to carry. I bought it as a demo from a closing tweeter when I was in my twenties. I hadn't planned on buying anything but I went into the store to see if there were any screaming deals and there it was for 60% off. I remember when the sales guy was helping me get it in my car I told him I paid the same amount for the sub that I did for the car. You gotta have your priorities straight. I carried it into the basement, out of the basement into an apartment, out of the apartment into another basement, out of the basement and up the stairs in another place. Finally, down the stairs and into the back of the family room where it is now.
Right after college when I was still living with my parents I bought an Infinity HPS1000 from ubid. I carried that 100 lb thing up the fire escape to the third floor. I was excited enough I probably could've done it with broken arms and legs. I had always wanted ATCs but I was never willing to shell out the money for one of the big active three ways. When a pair of 110s came up a few years back for an obscene price I jumped on them. I picked them up at the distribution center with my infant in the minivan. They loaded the pallet with a forklift. I got home and I carried those ridiculously heavy things into the living room to try out. A few months later I dragged them up the stairs to a bedroom that we used as a family room. Then down the stairs and into the family room where they are now.
I bet a lot of us have stories of physical pain we've endured due to our attachment to hearing music reproduced well.