> PiAlign recommends a bass reflex cabinet of 2.4 cubic feet tuned to
> 33.75Hz and having Q of 1.5. It recommends doing this using a 2.5"
> diameter port that's 2.75" long, which is very close to a perfect
> match - corresponding to Frd of 34.0Hz and Q of 1.56.

I just verified this calculs and unfortunately this doesn't work
for me. In your whitepaper for the port calculation I read:

Fre = 1/(2*pi)*(Ap/(Ve*Lc))^(1/2)

If Dp=2.5 and Lp=2.75, then Lc= 4.87,
if Dp=2.5 then Ap=pi*(Dp/2)^2 = 4.91,
and then for Ve=2.4 i have
Fre = 0.10312
and not 33.75 Hz as you said.
(Qe = 1.54 with no problem)

What's wrong ?

Thanks in advance,

O'Tor