Thanks for the input!

l=2.8m
ah=75cm2
am=850cm2

Could you please tell what ah and am (mouth area?) mean?

I used HornResp to model a conical horn for the "corner horn".

Actually, I calculated the vb (back chamber) and vf(front chamber volumes) and used the numbers in HornResp.

I just do not use the calculated front chamber volume yet. So if I need to conform to the numbers I would use Wayne's idea. See how small the throat area and the vaf are:

Input
fl = 15
fh = 150
fs = 20
qts = .21
qes =.31
qms = 2.2
vas = .82
QMC 6.816 (qmc is from calculation)

Output
vb = 0.177 m^3 = 6.25 feet^3
vaf = 0.0073 m^3 = 0.2578 feet^3
st = 0.064 m^2 = 0.687 feet^2
n = 36.39%

the vaf becomes bigger if fh is lower. I use these boxes as a subhorns so I will not reduce the vb (which will raise the fh and lower the n (efficiency). Another reason for choosing this vb volume is that I can get a volume around 6 feet^3 in a box shaped this way by using 4X8 board without much waste (a lot of 2X2 pieces are needed).

The way the "corner horns" are placed now gives a st of
0.85344 m^2 = 1.399308 feet^2 and probably a vaf of 2 feet^3. So I think I would use Wayne's idea to conform to the calculated st and vaf.

Maybe due to the lossy nature of the walls and the floors, all these numbers do not really apply. What really counts for me is the sound it makes. I got the room modes, but what other horn that goes this low would not in the same room?

Thanks!

Michael