Correctly guessed.
My pair of bl4 are the rear speakers in my setup. A pair of bl8000 stands at the front. The setup is under construction, so the subwoofer and a center is to come. I made the choise to use Beo only for sound distribution (and for watching in hours =) which means that I´m using a DeToma X501 digital sound processor as "brain" instead of the BeoVision-series for the dolby digital. Eventually, computer sound, DVD etc will be connected to the DeToma and distributed to the speakers.
So to be exact, the cables will go from my bs900 via DeToma to my bl4´s.
A new question then, how many pins are the powerlink Mk3 using? 4, 8.. etc? There are many fabricates that are making cables with din 5, maybe I could use one of them instead of Beo´s cables. But then I have to know that they are using the same pins.