Should work fine, but may be interesting to get the drivers in and out....... maybe you could zig-zag the path up the box and put the divers on top.I would assume the ripples would be due to mouth size, but if there is enough excursion in the drivers, a little EQ should be fine.
I have been thinking about a home use subhorn using 10" drivers myself, and am toying with the idea of going straight up the wall to ceiling height, using the horn as the rear of an entertainment unit (ie TV etc in front of horn as it goes up the wall - TV would sit on mouth opening section on floor).
Cheers
Graeme