If you think they're heavy now, just wait until you're mounting them and have to put your faith in the bracket. Don't worry. Mine haven't fallen yet.
Try putting them up with the "old" bracket, before they invented the super handy T hanger style.
Then you not only had to hang the damn things one screw at a time but you had to balance a carpenter's level to make sure it was all set up to snuff, dangle a spare wall screw in your mouth and manage to hang onto the power drill at the same time!!
Oh ya, we bought our speakers way back in the 'early' days.
We had to go old school
hanging those QS8s!!