So they should only be used in the Artic? [*-)]
In English, any time you have more than one driver doing the same thing you have a better chance of receiving varying signals to your ears. First each speaker is a different distance from your ear. And second, if there are any varriations in performace, each cone will not be vibrating identically.
Getting multiple signals is NOT a good thing.
IMO - Use a single driver whenever you can.
Now you have me worried. I opted to get a second identical subwoofer. I have them set up as master/slave. Do I have much to worry about as to polar response?
Would the subs sound better in Alaska or Antartica as opposed to Baltimore? I am willing to move for the sake of the sound.