An Odd Subwoofer Mounting????

This is what an isobaric setup looks like and dose http://www.maximacar.com/isobaric.htm but what I believe you are talking about is called  inverting a sub. Which is where instead of mounting the sub with the magnet in the enclosure, you mount it reverse with the magnet coming out of the enclosure. Now there are absolutely no benefits to mounting a sub this way other than looks. Now if you use this configuration you have to do two things. 1st  if you mount the sub that way it will be out of phase so in order to correct that you will need to reverse the polarity on your speaker connections +to- and - to +. 2nd you will need to subtract the displacement of the sub from your enclosures volume. Other than that the sub will sound the same and like I said before the only advantage is looks.

Ahhh...o k thank you all so far.  Let me see if I got this right. What bberman1 has stated toward the end of the post, is, basically I need to find out how much displacement my woofers basket and magnet take up and subtract that from the woofers recommended box size. (ex. 1.25cu.ft. box size - lets say .25cu.ft. displacement  = 1.00cu.ft. total with the sub invertedly mounted)  Did I get that right? I also understand reversing the polarity. Now although yes I will loose SPL, but can't I compensate that with a efficiant woofer rating? Thanks Again.

Sounds like you are on the right track. Some times the manufacture will give you the displacement in the owner’s manual. But if not you can get it by contacting their tech department. Personally I like the way some subs look inverted, if you have a nice magnet etc why not show it off.