Hello Leon.
The first downfall I see in such a design is requiring more
amplifiers for each box, designed around four drivers.
The second downfall I see is throwing away the whole concept
(Using multiple boxes to create one big horn), and trying
to get the most SPL out of a single box.
The third downfall is size. The box is praticulary 4 feet
deep already. Adding more size increases more truck space
which is not "A Good Thing" when you have amp racks, and
boards not fitting due to an over extended box.
Your project sounds better suited for possibly, the home
audio guy, whose limited space, can't house two labs.
For moving about, from venue to venue, I can't see what
I would be gaining going this route. I'll still need the
minimum of 4 boxes to achieve stellar results.
Maybe you can explain what I am missing here?
Best Regards,