Everything matters, it's just a matter of how much it matters...

I noticed something interesting a few years back when the Focal 5WS was reviewed in CA&E (I think). The lads at Focal asked that two of the four drivers be mounted inverted to help cancel out non-linearities in the motor and suspension systems of the drivers.

This isn't a problem specific to the Focals, most drivers work better in one direction, as compared to the other, most often because they are assembled with the voice coil not centered electrically in the motor. Found it interesting..