Box Design for DD 9512g?

[imhungnurnot 9]

First off, can I count on port end correction to lower the tuning freq of my enclosure? For example,

NET Vol. = 2.6 cuft. or 4493 cuin.

Port: 12.5" wide x 3.375" high X 24" long

without end correction, (port length = 24") tuning = 38.58Hz

with end correction, (port length = 25.6875") tuning = 37.52Hz

I know 1Hz difference in tuning isn't really audible (but the end correction factor will differ in different situations i.e. port height, etc), but I want to know if the end correction factor actually exists!!!!

Secondly, I'm about to build a box for one DD 9512g. DD recommends 42 in^2 port area with 22 port length with 2.6 cuft NET vol. which yields 39.97 Hz tuning frequency or 38.79 Hz w/ end correction (using 12.5" wide x 3.375" high)..

This tuning seems pretty high.. I listen to rap/rock so I would like the sub stage to be able to play over a fairly wide range of frequencies having okay output on the higher freq. but still get pretty loud on the lower freq.

Personally.. I was thinking 36 Hz counting end correction so that would mean the physical port length should be about 26.625"

So what should I tune to using 2.6 cuft NET Vol. and a 12.5" wide x 3.375" high slot port?

[imhungnurnot 9]

help please..

[imhungnurnot 9]

BUMP

[Kanaworm$ 292]

38-40 hz

[imhungnurnot 9]

38-40 hz

Why so high though? Many people on here tune below 35.

[Kanaworm$ 292]

38-40 hz

Why so high though? Many people on here tune below 35.

DD recommends the high tuning, Why? I have no idea ....

[imhungnurnot 9]

38-40 hz

Why so high though? Many people on here tune below 35.

DD recommends the high tuning, Why? I have no idea ....

built a box 2.52 cuft @ 36Hz and it slams!