Are you using optical, or RCA?
You may be able to connect all your devices to the TV, and then send the signal out through the optical or audio out. With the Un55B6000, there is an analog (#11) in the diagram below that can go either to another 3.5mm male jack, or to an RCA, depending on what the Polk soundbar has:
Let me know if I can assist further.
I am trying to connect my Polk SurroundBar SDA Instant Home Theater to my Samsung UN55B6000. Right now I have it going through the cable box. I also have a Samsung Blu Ray but I have to listen to that through the TV's internal speakers. Is it possible to connect all three. Thanks