What does the Bose system control do for the subwoofer. I'm not getting any sound from the subwoofer. I bought another subwoofer but I'm still not getting any sound. Then, I bought a new system control cord and it's still not working. Any suggestions??? I've already checked the soldering for the system control and it looks fine. My take on the system control 1 and 2 is that it acts like a switch to turn on the subwoofer...Please help