The sound I get when I turn on the sub doesn't go away. It stays on until I turn the sub off, and it's not faint. I stopped after the first amp when this came up, so no, I haven't demoed.

You described the wiring fine. The issue I had was with the instructions telling me to hook them up to the right side and left side of the woofer when the sets of terminals are on the top and bottom of the woofer, which would mean having one wire from a set going to the top and another going to the bottom. However, if the instructions were written with the horizontal config in mind, then I imagine it would keep the set of wires with the same set of terminals.