Does anybody know if the signal from the subwoofer outlet on an Avant 28 vcr Rf with dolby digital is a single signal or stereosignal?

I want to use a non B&O sub ( cannot afford Beolab2 right now). This sub has a line in with one cinchjack. I am thinking to make a powerlink cable with at one end a powerlinkjack and at the other end a cinchjack, but this will let through just one signal.

Is this possible? Somebody who has done this before?

Thanks, Willem

Thanx Stig!