Box making experts!

Blackie, forbidden has shown you the light.  You are probably not inputting parameters correctly in the program;  for example, Audiobahn lists SD as M2, where most programs want cm^2.....so a listing of .044 M2 would translate to 444 cm^2.  And possibly some other things, too.  Take the considerable trouble to get all inputs correct.

You also must know how these two subs are going to be connected if you are going to work up your own design....which is why I asked you in the beginning how the wiring was going to be done.  You didn't answer that.  If I were designing an enclosure I would input that necessary information.

Use the site's tech support, go to 2004 Flame Compression, you have a choice of seeing PDF files for T/S parameters, suggested box specs and graphs.  Use this information as it is already figured out for you.  As forbidden has stated, the total cubic feet for one sub would be 3.5.  Notice that they are kind enough to give you both net volume of 3.15 and total volume including port and driver displacement. 

Look at the box sizes, etc, given and choose the one with the response and size that will suit your purposes best.  To build for two subs instead of one, separate the box into two chambers so that each chamber has the physical characteristics as outlined in the Audiobahn help.  The two chambers must be sealed from each other.

winisd already has the subs info in its list of subs that it gives you in the begining. are you saying that the information may not be right and i should enter in a "new sub" parameters?  Also if i just choose one sub on win isd it give me this  ---->  internal volume of .5 cubic feet and a port with a 4 inch opeing thats 75 inches long!!!! that makes no damn sense and doesnt match audiobahns specs at all??? I also double check all the T/S parameters and they are right.  What else could be wrong??  if i cant figure this out soon i will just make two seperate boxes with audiobahn recomendations, but i really wanted a to do a single port mono box, can someone enter the aw1208T into winisd and see what they come up with??

Read what I wrote in https://www.the12volt.com/installbay/forum_posts.asp?tid=50823&KW=WinISD

Everything you're asking is explained in the Help section of WinISDPro.  And yes, the parameters may be incorrect, so don't assume they're right.  Picture this:  the author of this program entered all those parameters for all those speakers himself.  I can picture his eyes getting a little bit blurry by the time he got to the 30th Audiobahn model...

...and you'll see that I mention this 'recommended 4" x ___" ' port size in that thread.  After reading what I said you'll understand more on how you are supposed to use the program.

Besides all that... and I hope you read the linked thread and the entire Help section in WinISDPro.....you can easily convert the ports needed for two enclosures into one port for one combined enclosure.  There are some calculators that help with that, some of which I linked to in that thread shown above.

What am I doing, talking to myself here??

Nope, that would be correct.  In a 0.5 cuft enclosure with a 4" port tuned to 29.5Hz, the port needs to be 75 inches long.  Not a very logical setup, eh?  It could be done, though.  I'm thinking a snorkle port...

The real problem is the T/S parameters given by Audiobahn are not correct.  Those compression drivers exhibit really strange behavior and I will bet you a brand new bananna skin trombone that if you measure the actual performance for one of those drivers you'll get numbers WAY different from the published specs.  33l Vas for a 12" driver?  Kinda small.  In any case, just do what Audiobahn recomends and you'll get the best you can out of those things.  They are really only good for high SPL noise anyway, so it's not like you're likely to hear any difference no matter what you do!