I recently built a push pull T-line sub woofer following someone else's design. Both our designs have both 4 ohm drivers facing the same direction (one mounted outside the enclosure and the other facing the same direction but mounted inside the enclosure (in a I< I< fashion). The originator of the design states that these two drivers should be wired out of phase. It seems to me that they should be wired in phase. which is correct? If the speakers were instead mounted in a I< >I fashion or a I> I<, it would seem that they should then be wired out of phase with each other. Would appreciate advice and an explanation.