The jumper bars are only on the 2 big speakers btw, the central and back ones don't have those.
But still besides that, its probably easier to keep those connected to the avr, since I assume I can't change volumes from individual boxes anymore trought the avr if I would connect the speakers to the converter.
Well thanks guys! I will look into a hardware store tomorrow to see if I can find any of those and otherwise buy it online.
Thanks for the help! I never thought all this stuff was this complicated but I'm glad I got some help with it