When I look at the motherboard - there are pins labled SPEAKER - 4 pins just like the wire. On that set of 4 pins - the bottom pin has a black X.
Thats interesting I never noticed that. I just checked my pins and they do indeed have a triangle on them. I cant see the black X on the motherboard you are refering to though... I just go by the +/- signs. I assume the coloured wire are + the black/white wires are -.