I have one of the new sterling sub ax series guitars and I love it. My question is about the pick up selection. With the 5 way blade switch I know that POS 1 is neck, POS 3 is both pickups and POS 5 is bridge only. What does position 2 and 4 activate? In these other 2 positions, while tapping the coils with somthing metal, they still seem to be in humbucker mode (not split) into single coil