Hi Steve,
Unfortunately, no-one from B&O has responded to me to clarify the situation regarding the Powerlink input on the S8 Hub, so this socket is best ignored to give you simpler operation for your speakers.
To clarify, Beolab 14 does not have a surround sound processor, it simply has multiple power amplifiers built in. The S8 Hub is a stereo pre-amp only, so it will give stereo sound to a Beolab 14, not surround sound. To get surround sound from a Beolab 14, you need a full surround sound processor or pre-amplifier.
If you need any help with cables for your system, please contact me directly at