Ok, per earlier post the new subs don't have the dip switches or a port for remote gain control. I still connected to the subwoofer lines, much easier in the read passenger area of the vehicle AND... It was toooooo much bass. Even setting the bass as far back on the stereo as possible it was too much. Switching the phase helped - a little. But it was still too much unless listing to hip hop. It sounded really good with that FWIW. I eventually tapped into the yellow and yellow black, played with the phase through a few different genres and it is much better to my ears.
If you go to the rear seat passenger kick plate to access the wires it bends up easily and it gives you access to both the yellows and the green/blue. If you have a newer unit without the ability to add a remote gain control, the yellow maybe the way to go to get a more even sound.