In light of recent events you need the MoM sub and FoF.
For the MoM you take a male motor that has it's power increased by stacking an extended pole piece up the pole vent of the first sub. Male on Male subwoofer is born. Give discounts on sub care plans and rimcones.
Female on female subs you just have to have a pole piece that straps to one pole vent and into the other pole vent. Has to be a strap because we all know scissor mounting does nothing.
People will complain and get butt hurt because it's not how subs were intended to be built