imagine this... you have a scale with an empty jug of either side. you have a 3" tube running across the jugs but one of the jugs has a 1" tube coming from the 3" tube and the other just has the 3" tube. now the tube is your wire, the scale is your box and the jugs are your subs.
following me so far?
now you run water (power) through the tubes. the one with the 3" inlet would fill faster correct? then the scale would tip all the way over.
so in the box, the subs wouldnt be balanced and they will actually fight each other.
as for the "almost the same just a different motor and magnet and coil" those are the important things. the cone doesnt mean dick. and the magnet is the motor.