Please help with corner loaded 6th order bandpass design

So now I need some low end to compliment my unity horn (see sig). I have subwoofer coverage to 80 hz, and the horn starts rolling off around 300 hz, so my goals are as follows:

-corner placed box with unity horn mounted directly on top

-6th order bandpass: smaller than a tapped horn, and fits my theater layout the best. It's also a great distortion filter on both low and high end. See pics of proposed design. I've never built one, and I hear they are pretty tricky to get right. Sims with WinISD are limited.

-Kappa pro 15 LF-2: pic #1 shows my measured T/S parameters, which hopefully are reasonably accurate. I already own this driver and will use it for whatever solution shakes out, be it this box or something else.

F3 (low) 65-70hz
F3 (high) 300-320hz

The box will house a horizontally mounted driver. The high bandpass will occur in a non ported chamber whose width is that of the unity horn's outer flare.

I'd like to know where to place the lower band pass port. In general, should it be near the floor, off to the side where the subs are, or nearest the higher bandpass chamber? Round or rectangular? How wide?

Thanks,
John

Thanks, LTD02. Looks to me like all the ports are up front in those designs. I had toyed with the idea of a rear lower port, but I would assume that such an arrangement would add yet another layer of filtering: the distance from the port to the walls (corner) would create further band passing, likely highly sensitive to the speaker's distance from the corner. I think I'll build a test mule out of OSB with all ports forward, as close together as possible... stay tuned.

John

I remember reading that a downfiring woofer will sag over time. Does anyone know if "sag" is as much a problem with upward firing drivers? Maybe I should just plan on a horizontally mounted design- as I'm in the design phase, this is not really a huge deal at this point.

John