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View Full Version : DXi124 SVC 12" Ported box design, help!



Bernick
04-17-2013, 10:14 PM
I used WinISD Pro to design a box measurements seem okay but graph seems way off. With my peak frequency of like 90hz which seems wrong.

-Tuning Frequency- 30hz
-Internal lengths
Depth-20
Width-18.5
Height-14.5
-Volume- 2.283 Ft3

If someone is familiar with this sub and or has build a ported box for this driver and would kindly look over it that would be a great help THANKS!

I would post a link to this sub spec sheet but im to new to be able to. Im just getting into different audio related things and would like to do this right the first time
specs are on Page 23
Thanks if anyone helps

NIHL8ION
04-17-2013, 10:30 PM
What is your port height, width, and length? Or if round ports what diameter and length?

Bernick
04-17-2013, 10:35 PM
What is your port height, width, and length? Or if round ports what diameter and length?

Port height- 14.5 internal
Port Width- 2.5
Port Length- 42.37

NIHL8ION
04-17-2013, 10:48 PM
Port height- 14.5 internal
Port Width- 2.5
Port Length- 42.37

few things... 1st -you can't have your port height the same as the overall height of the enclosure (You must subtract the thickness of the building material in question for top and bottom, so it this is a 14.5" tall enclosure and you are using .75" mdf or birch as your building material, than your port height will be 13" - 2nd - How do you want this box to be setup? Sub mounted to the front? top? Port exiting side, front? Also - The recomended polk enclosure calls for 1.5 cu ft. and a 4" x 10" round port which if you do the math comes out to like 41-42 hz tuning...

Bernick
04-17-2013, 11:09 PM
-I know my port height is 14.5 but external is 16.
-I would like to mount it front facing.
-I am trying to get between 28hz and 35hz for mostly hiphop.

Do you have a suggestion for what my enclosure dimensions should be? Because this was my first time at it. So I was trying to make sure I did it right the first time. And by the way thanks for the help!

NIHL8ION
04-17-2013, 11:25 PM
OK... Well let me see here... Polk recommends 1.5 cu ft @ roughly 41-42 hz tuning... You are wanting to go bigger and lower correct? I can NOT say that I KNOW for a fact how that will result in the end without testing... All I Do know is that I wouldn't go too much bigger... What are your desired outer box dimensions again - I think above got skewed cuz that's why I asked about port height in relation to your box height...

NIHL8ION
04-17-2013, 11:58 PM
-I know my port height is 14.5 but external is 16.
-I would like to mount it front facing.
-I am trying to get between 28hz and 35hz for mostly hiphop.

Do you have a suggestion for what my enclosure dimensions should be? Because this was my first time at it. So I was trying to make sure I did it right the first time. And by the way thanks for the help!

This should get you right around to, or at least close to: where you're looking to be...

http://i1187.photobucket.com/albums/z396/NIHL8ION/PolkDXi12Enclosure_zps2d369b0f.png

Bernick
04-18-2013, 08:19 AM
Okay thanks I will try this out. Do you think I should make my port larger then 1.75?

NIHL8ION
04-18-2013, 08:32 AM
Go and do a google search for "Torres Box Tuning Calculator", you can also use RE AUDIO - Box Calculator (http://reaudio.com/box.php) for the type of box you are building and play with the sizes to see what the tuning freq. will end up as... For that size box, going larger than 1.75 ends you up having a longer port than you can make an L with for that box size to get any where near your desired freq range, I suppose you could do a labyrinth style port maybe, but I have no way to calculate something like that with these basic tools...

Bernick
04-18-2013, 09:41 AM
Go and do a google search for "Torres Box Tuning Calculator", you can also use RE AUDIO - Box Calculator (http://reaudio.com/box.php) for the type of box you are building and play with the sizes to see what the tuning freq. will end up as... For that size box, going larger than 1.75 ends you up having a longer port than you can make an L with for that box size to get any where near your desired freq range, I suppose you could do a labyrinth style port maybe, but I have no way to calculate something like that with these basic tools...

So you saying I should go with the dimensions you suggested.

NIHL8ION
04-18-2013, 06:28 PM
So you saying I should go with the dimensions you suggested. I'm saying if you go bigger with the port, you will in turn need to make the box bigger as well to get to your desired tuning frequency... My suggestion is already bigger than polk recommends for that particular sub, but not by a crazy amount... I've asked a few other installers I know if they've dealt with these subs & what the results were but I can't seem to find anyone who has experimented with this sub and enclosures for it first hand... I've only heard this sub in a loaded polk enclosure, I've never had anyone request a custom enclosure for one of these... Just trying to help you out any way I can, I will let you know if I find out anything else...