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Bggd_GMC
11-05-2011, 12:41 AM
welll did more research and if my math is all correct i have 1.75cf after sub and port displacement...BUT i dont know lol look over it and see if im right??? the12volt said i need 26.8in of port but rounded it off to 27....


box is 15h, 15d, 24.5w INSIDE 13.5d, 13.5h, 23w.....tuned to 30hz

box=4191.75

port=911.25

sub=.14


4191.75 - 911.25 = 3280.5 / 1728 = 1.89 - .14 = "1.75"

am i right? =D

mylows10
11-05-2011, 01:06 AM
2.5215 x15 x24.5 =5512.5 - 911.25 = 4601.25 //17282=2.6627 - .14= 2.5227 cubic ft

Bggd_GMC
11-05-2011, 01:21 AM
what did i do wrong>?

mylows10
11-05-2011, 01:23 AM
not sure but thats what i came up with 4 times

Bggd_GMC
11-05-2011, 01:30 AM
not sure but thats what i came up with 4 times

ahhhh ok.... the outside box is 15x15x24.5....i was doing 13.5x23x13.5

mylows10
11-05-2011, 01:39 AM
even with those measurements ,still 1.99 cubic feet

Bggd_GMC
11-05-2011, 01:45 AM
hmmmmmmmmmmmm

mylows10
11-05-2011, 01:49 AM
go to the re box calculator and put in the measurements then minus displacement.it's easier that way.but you are close

Bggd_GMC
11-05-2011, 01:55 AM
biggggggo headache

mylows10
11-05-2011, 02:00 AM
yea i know but you should be ok still with your measurements , re says your port is only 1.5 " wide for 30 hertz.i know their calculator is off a little [the tuning ],but should still be close.

Bggd_GMC
11-05-2011, 02:01 AM
i dont think i did my port displacement correctly

mylows10
11-05-2011, 02:05 AM
what is the port size

Bggd_GMC
11-05-2011, 02:07 AM
1.75 wide

mylows10
11-05-2011, 02:09 AM
how long

mylows10
11-05-2011, 02:10 AM
31" long at 1.75 for that freq

Bggd_GMC
11-05-2011, 02:11 AM
31" long at 1.75 for that freq

31"? **** lol 12volt said 27

mylows10
11-05-2011, 02:13 AM
start at 31 dont glue the top on so you can adjust if needed

chillin
11-05-2011, 02:14 AM
I got 1.76 using the op's measurements. That's assuming his port calculation was right.

Bggd_GMC
11-05-2011, 02:15 AM
gotcha

---------- Post added at 01:15 AM ---------- Previous post was at 01:14 AM ----------

what if i do aero ports insted of slot?

Bggd_GMC
11-05-2011, 02:18 AM
I got 1.76 using the op's measurements. That's assuming his port calculation was right.

i did 13.5 x 27 x 2.5 for the port

mylows10
11-05-2011, 02:19 AM
gotta be careful of port noise then

Bggd_GMC
11-05-2011, 04:25 AM
http://i82.photobucket.com/albums/j270/oak_03/tyjutyju.png

pro-rabbit
11-05-2011, 09:34 AM
1.75" wide port width is very skinny, in most cases to skinny.

What sub are you using again?

mylows10
11-05-2011, 10:28 AM
I agree on the port size

Bggd_GMC
11-05-2011, 07:35 PM
1.75" wide port width is very skinny, in most cases to skinny.

What sub are you using again?


sa12 4 ohm

pro-rabbit
11-05-2011, 08:50 PM
Way to small port for that thing.

Bggd_GMC
11-05-2011, 11:54 PM
im going to do a shared chamber box

pro-rabbit
11-06-2011, 10:22 AM
How many subs are you using? That port area is small for one sub already if you are going to try and use more then you really need to open up that port.

wenn_du_weinst
11-06-2011, 10:23 AM
Subwoofer Enclosure Calculators, Fraction to Decimal, Parallel, Series, Port Length and Volume Calculators (http://www.the12volt.com/caraudio/boxcalcs.asp)

use this not RE junk calculator

Bggd_GMC
11-06-2011, 03:53 PM
http://i82.photobucket.com/albums/j270/oak_03/jytjtyj.png

http://i82.photobucket.com/albums/j270/oak_03/kyukyu.png

Bggd_GMC
11-06-2011, 03:56 PM
How many subs are you using? That port area is small for one sub already if you are going to try and use more then you really need to open up that port.

everything i posted was for 1 sub in its own chamber.... im doing 2 subs in there own chamber with a 1.75 port each

pro-rabbit
11-06-2011, 07:03 PM
everything i posted was for 1 sub in its own chamber.... im doing 2 subs in there own chamber with a 1.75 port each

Try and do a single port if you can. Also what is the over all size of the port?

I personally wouldn't use a 1.75 wide port unless it was 100% necessary.

Bggd_GMC
11-06-2011, 07:59 PM
Try and do a single port if you can. Also what is the over all size of the port?

I personally wouldn't use a 1.75 wide port unless it was 100% necessary.

what about 3.5cf after all displacements single chamberd with a 3" wide port tuned to 30hz? theres pics in the 2nd page

Bggd_GMC
11-07-2011, 03:01 AM
anyone >_< this is the only thing that is holding me back everything else is just basicly bolt on except this box so i just want to get it over with... some stressful stuff last time i try to do a ported box lol

Bggd_GMC
11-07-2011, 04:00 PM
......

Bggd_GMC
11-07-2011, 05:53 PM
just need a confirmation and ill get to building

http://i82.photobucket.com/albums/j270/oak_03/xcvvx.png

http://i82.photobucket.com/albums/j270/oak_03/new.png

pro-rabbit
11-07-2011, 06:02 PM
Looks good, but how far is the T part of the enclosure from the back wall? And if you could, I would try to get a 4" wide port if the length and displacement is not to much for your space.

Bggd_GMC
11-07-2011, 06:05 PM
Looks good, but how far is the T part of the enclosure from the back wall? And if you could, I would try to get a 4" wide port if the length and displacement is not to much for your space.

the port is also 3.5 from the back wall... ill see if i can mess with a 4in port

pro-rabbit
11-07-2011, 06:07 PM
It needs to be half the width from the back wall when you do a T port like that. If you do a 4" that puts the back part 2" from the back wall which is what I would shoot for in your build.

Bggd_GMC
11-07-2011, 06:29 PM
It needs to be half the width from the back wall when you do a T port like that. If you do a 4" that puts the back part 2" from the back wall which is what I would shoot for in your build.

like this??? i dont think the 4in port will work lol

http://i82.photobucket.com/albums/j270/oak_03/ehyerh.png

pro-rabbit
11-07-2011, 06:31 PM
On the 4" version you have to turn the end to come back forward to keep the 2" width available. Also are you dividing out the remainder of the port length(When the T starts) correctly? Looks like you are just putting each side to the full length.

Bggd_GMC
11-07-2011, 06:38 PM
On the 4" version you have to turn the end to come back forward to keep the 2" width available. Also are you dividing out the remainder of the port length(When the T starts) correctly? Looks like you are just putting each side to the full length.

so how would i do that??? port length is 55.5" so 13.5 deep and 21" for each side 13.5 + 21 +21 = 55.5

pro-rabbit
11-07-2011, 06:40 PM
What are the dims on your enclosure you working with? Let me check what you have and I will let you know.

Bggd_GMC
11-07-2011, 06:44 PM
what are the dims on your enclosure you working with? Let me check what you have and i will let you know.

15h, 14.25d, 50.75w

pro-rabbit
11-07-2011, 06:55 PM
I'm only getting 4.9 gross. Can you go any larger? Just a bit to 5.2-5.3(ish) gross. Port would be 13.5 x 4.5 and 27-28 long depending on tuning.

When you get to the back of the enclosure you subtract your port you already have so you have a total of 27" needed. If you stay with 14.25 deep you would have a 10.5 length. So you still need to create another 16.5" of port. Being that your port would be 2.25" from the back wall you divide your 16.5 by 2. This gives you 8.25 per side you need for length.


And that is my free design/lesson for the week haha.

Bggd_GMC
11-07-2011, 07:04 PM
yeah i can get 5.28 and thats pushing it, if im off by 1/8in it wont fit between a crease i have in my bed lol

Bggd_GMC
11-07-2011, 07:09 PM
thanks man for the help im going to do another of those rendering things with what you told me!

pro-rabbit
11-07-2011, 07:13 PM
Are you doing a blow through?

Bggd_GMC
11-07-2011, 07:18 PM
im doing a blow through. would it be 8.5" long each side for 30z?

pro-rabbit
11-07-2011, 07:21 PM
The model I did was 8.25 per side at the T for 33hz if you wanted to do 30 hz it would be closer to 12" per side at the T

Bggd_GMC
11-07-2011, 07:28 PM
alright ill do 12 per side... and i just subtract to the port and woofer displacement to find the net of the box correct?

pro-rabbit
11-07-2011, 07:29 PM
Yep, I had done all that math for you though except for the 30hz version. I was making an educated guess at it. lol

Bggd_GMC
11-07-2011, 07:35 PM
ill figure it out lol