Hi, I have a problem choosing the right speaker outlet for my subwoofer. I am planning on getting Jamo Sub 300 this is the subwoofer cable that I have: And these are the wall plates that I can choose: - I had bought this one but returned it because my technician told me that the cable is shielded and the outlet is not and also that you need 4 connectors to connect a subwoofer... so I should get one of those: - but you need TWO speaker cables to connect it and I only have one cable running in the wall. What should I do? How do I connect the subwoofer? Will one of those outlets be fine, or shoud I buy an adapter of some kind etc.? Thanks for the help!