Port HELP!

[Dangercdv 4]

I am designing a custom box I want tuned at 32 hz and I am not sure if I am using these online calculators correctly.

I enter my box volume and height and width of the port and it gives me the length i need to make it...

my question is what is my box volume? It is with or without the port???

My box is all completly designed and ready except for the port length because I am not sure how to get my desired frequency.

Here is my current box.

Height= 15 inches

Width= 17 inches

Depth= 20 inches (I might lower depending on how much I need for port)

Port height = 13.5 inches

Port width = 2 inches

if this enclosure was SEALED, its total volume = 2.24 cubic feet, i was aiming more toward 1.75-2 feet. but i know the port takes room.

PLEASE HELP.

Edited December 31, 2012 by Dangercdv

[aleroking 0]

that port size isnt going to work

you could do 9.5" tall 2" wide 27" length (it will have to be an L port)

that would bring you down to 1.66 net volume

tuned to 32hz

11.45 port per ft

you also need to account for sub and bracing displacement.

[ssh 924]

Gross volume is the volume of the enclosure before any displacements (port volume displacement, driver volume displacement, bracing, etc).

Net volume is the volume of the enclosure after all displacements.

Port tuning is based on port area, port length, and enclosure volume. The latter must be net volume since the port displacement alters this number.

This should help: http://bitpusher.in/?p=ported

[aleroking 0]

using that size port you said the best you could do is

30" long which would be tuned at 40hz (to high imo)

20in port per ft (way too much)

and net would be 1.35 before sub displacement

[StreetLegal 119]

Total internal volume of box = (net volume) + (woofer displacement) + ( port volume = wood + air) + ( braces & 45's if applicable)

Net volume is the volume the woofer see in the box after all displacement, which is recommended by most manufacturer, say for example, for a 12'' sub the net that can be used is between 1.75 to 2.5 cuft.

[Dangercdv 4]

okay, this is my box right now and it seems to work.

IF IT WAS SEALED, it would be 2.24 cubic feet.

20 inches deep, 15 inches high, 17 inches wide.

27 inches of port (18 deep, 9 wide) which tunes it around 32.

Would this work, there is about 1.7 cubic feet after I subtract the port.

It is ment for a SA-12 which could go down to 1.5, so will this work?

Edited December 31, 2012 by Dangercdv

[Dangercdv 4]

Height (15 inches)

Width (17 inches)

Depth (20 inches)

Port = 2 inches wide, 27 length.

Tune = 32hz

3/4 inch wood

Volume = ~1.7

Edited December 31, 2012 by Dangercdv