reverse toner phase at the x-over point

[fjc]

I like to confirm the way to reverse a phase at a crossover design.
In x-over design, often we try to reverse the phase by reverse the polarity. For example, during a 2 way design with 3rd order toner, first order mid-bass, we switch the polarity to change the phase 180 deg. to make phase match at the crossover point, it was considered a smart move..

I like to confirm the procedure of either
1. just reverse the polarity +/- of one of the spk component,say toner.
or
2. reverse the +/- pole of the toner crossover circuit of one of the x-over system, not the spk part .
Which is proper.
I think choice one should be correct.
pls confirm.