Synergy style horn for a sub?

[NBPK402]

I am currently working on some 2' cube synergy horns with 2 15" Celestion woofers. I currently have them installed in a pair of k402 MEHs, and the performance was so good, it gave me an idea...what if I make another horn 2' wide x 36" high and the same depth as the k402? Now the idea is 2 put 2 15" Celestions on each side of the horn (stacked on top of each other), and then 2 stacked on top of each other on the throat of the horn. Then run the ports as normal with 2 oval ports per woofer. The rear area where the compression driver normally would go would need to be 6" wide instead of 2" wide....with 2 slots side by side or 1 large port that would, give the same compression ratio  as the MEH ports do. By going this way I would have 6 15" woofers for each MEH, and I am assuming 6db more output at 20Hz with a total of 8 woofers per channel vs 2. 

I came up with this idea when I saw a DIY sub that Pass had made that was an open baffle...with a stack of woofers on each side feeding a "U". I kept looking at it and how similar it was to my first OB k402 MEH. I would not go OB, but enclose the wood horn the same as my mini MEHs will be, but instead of 24" high...make it 36" high. This would then put my Mini MEHs at close to ear level, and make them closer to being flat from 20hzto 20khz (with over 100db efficiency for 20hz to 20khz). I could also just make the sub with 2 or 3 woofers and get a 3db increase and take up less height.

I do not have the software nor do I know how to calculate the outcome...just going by the performance of my MEHs, and adding 3db for every doubling of the number of woofer drivers.

 

Ideas, problems, comments?