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norcalSRTrida
07-10-2005, 04:54 PM
check for any problems in my dimensions, and port length.

whats not stated:

Not To Scale.

Port Size: 13" H x 2" W

inner port wall that is not stated: wall length should be 12.54"

comes out to be 2.8ish^ not 2.7 (not that it will make a big difference)


http://img209.imageshack.us/img209/8255/subwooferboxdimensions6xa.th.jpg (http://img209.imageshack.us/my.php?image=subwooferboxdimensions6xa.jpg)

see any mistakes or anything? this is my 1st time creating box plans, so i want to make sure there are no errors.



im ready to start building this box for my avalanche 12, but im hesitant due to the fact that im not sure that the port length is correct. i got the # off of winISD using the rl-p as the driver as for, i couldnt not find the avalanche driver in the folder.

davidfre21
07-10-2005, 04:58 PM
left and right sides are correct?

davidfre21
07-10-2005, 04:59 PM
i see a problem with the back and front also?

something just doesnt look right

norcalSRTrida
07-10-2005, 05:06 PM
well remember im using 3/4" mdf, so i subtracted either .75 or 1.5" from each given #.

i have plans written out as well for the front view of the box and the side view of the box, if i need to scan them in

let me know what doesnt make sense so i can help out.


and where at in cali are you located? if you dont mind me asking





-mike

norcalSRTrida
07-10-2005, 05:13 PM
im pretty sure everything is mapped out correctly. i am not sure if the port length is correct being at 24.54, and if it is, if i even created the port walls long enough.

davidfre21
07-10-2005, 05:15 PM
newman, bout 20-30mins from tracy...

davidfre21
07-10-2005, 05:18 PM
i was going off ur drawings scale but if i look at it only thing that doesnt seem to work in my head is how 29.5 + 2" port + port wall = the back wall :)

norcalSRTrida
07-10-2005, 05:19 PM
newman, bout 20-30mins from tracy...


o, **** pretty close.


do you create boxes by any chance?

i'd really like to figure out my port length and try and build it myself tho.

PhatTonyDeMarco
07-10-2005, 05:22 PM
i was going off ur drawings scale but if i look at it only thing that doesnt seem to work in my head is how 29.5 + 2" port + port wall = the back wall :)


29.25 + 2 = 31.25 + .75 for the port wall = 32
Back Wall + 1.5 for both sides thickness = 32

;)

norcalSRTrida
07-10-2005, 05:22 PM
i was going off ur drawings scale but if i look at it only thing that doesnt seem to work in my head is how 29.5 + 2" port + port wall = the back wall :)



thats the front wall.

i have the front wall that is 29.25" + 2" of port space + .75" left hand wall = my 32" of width

then i have my port length that i assume is 24.54".

so i went 12" back and 12.5 inches to the right to complete my port.


i duno tho, im 16, nd this is all new to me. im just trying to catch up and figure out all this stuff.

norcalSRTrida
07-10-2005, 05:23 PM
29.25 + 2 = 31.25 + .75 for the port wall = 32
Back Wall + 1.5 for both sides thickess = 32

;)




bingo

davidfre21
07-10-2005, 05:26 PM
ur drawing confuses me lol, i cant design the boxes but they are too bad to make. I made my first ported box couple weeks ago:)

u going to the tracy/best buy comp on the 30th?

norcalSRTrida
07-10-2005, 05:28 PM
ur drawing confuses me lol, i cant design the boxes but they are too bad to make. I made my first ported box couple weeks ago:)

u going to the tracy/best buy comp on the 30th?



i dont understand what does and what part confuses you.

all the numbers stated i had to subtract .75" or 1.5" due to the 3/4" wood being used.

so like the back wall 30.5 inches wide because i subtracted 1.5" from it from the walls. add 1.5" to 30.5 and i get my 32" width

all i need to figure out is the correct port length, and i keep getting different #'s between 24-26"


and *****, didnt even hear about the comp. i might show up, but ill feel stupid.

ill have my trunk empty w/ a lonely amp sittn in the back while i wait for my sub to come in.

davidfre21
07-10-2005, 05:31 PM
ur drawing is correct i was just looking at it wrong :)

when is ur sub due in? and what sub?

norcalSRTrida
07-10-2005, 05:32 PM
ur drawing is correct i was just looking at it wrong :)

when is ur sub due in? and what sub?



i ordered my AA ava12 last week. should come in not this coming week, but hopefully the following week.

so my port length seems just?

davidfre21
07-10-2005, 05:36 PM
i couldnt tell u about the port length, i had help designing mine...

u have plently of time to get ready for the comp :)

u would be in the Stock 0-300

norcalSRTrida
07-10-2005, 05:40 PM
i couldnt tell u about the port length, i had help designing mine...

u have plently of time to get ready for the comp :)

u would be in the Stock 0-300



hopefully itll all be done by then. ill be going to the shop and gettin my HU this week, then all i have to do is create my box.

you going to be there?


we'll have to exchange info or find out what car you drive so i can keep an eye out



any1 else care to help me dilemma w/ my port length?

davidfre21
07-10-2005, 05:42 PM
oh u know ill be there in the stock 301-900 class.

norcalSRTrida
07-10-2005, 05:47 PM
oh u know ill be there in the stock 301-900 class.



:( sadly enough, i dont know the classes at all.


i just got into car audio nor more than 2 months ago, and been trying to get everything down.

all these class names just seem like #'s to me. lol


drop me a pm a day or two before you go, and ill let you know if my systems done by then.

norcalSRTrida
07-10-2005, 07:03 PM
no1 has an idea of what my port length should be?

and can some1 give me a discription of what correctional factor is?

bcarpenterfhl
07-10-2005, 07:50 PM
i have been able to figure out what your trying to tune to...

norcalSRTrida
07-10-2005, 08:05 PM
i have been able to figure out what your trying to tune to...



2.8^3 @ 30 hz


ive got 25.19" and 24.54 in another program

im about to add those 2 up and / to get the avg and just use that number. lol

any idea

bcarpenterfhl
07-10-2005, 08:07 PM
you're gonna compete with a box tuned to 30 Hz? Have you figured out the resonant frequency of your car?

norcalSRTrida
07-10-2005, 08:11 PM
you're gonna compete with a box tuned to 30 Hz? Have you figured out the resonant frequency of your car?


nope. im a newb to box building, i just planned on building a box tuned to what i want and placing it. lol


how do i figure out resonant freq.?


edit:


i dont plan on competing in any comps. and if i do, itd be jsut for the hell of it

bcarpenterfhl
07-10-2005, 08:16 PM
you usually want to tune close the the resonant frequency of your car. i've never competed, so dont hold me to any of this. but to find the resonant frequency of your car, i believe you place your sub in a sealed box built to specs, then play a sweep of different test tones. then with an spl meter from radioshack or something, figure out which test tone frequency plays loudess (remember to keep the volume on h/u constant). the frequency that played the loudest is your resonant frequency (it usually ranges from 40-55 Hz). Then i believe you try to tune your box a quarter octave below the resonant frequency or something. but ask someone who competes, they'll know more than i do.

msimon
07-10-2005, 08:22 PM
I think you are measuring your port length incorrectly, I get 28.29" after the correction factor. When you measure length you don't go by the length of the port walls, you go by the length of the middle of the port, like this:

http://img253.imageshack.us/img253/1209/subwooferboxdimensions6xa0yo.th.jpg (http://img253.imageshack.us/my.php?image=subwooferboxdimensions6xa0yo.jpg)

norcalSRTrida
07-10-2005, 08:33 PM
I think you are measuring your port length incorrectly, I get 28.29" after the correction factor. When you measure length you don't go by the length of the port walls, you go by the length of the middle of the port, like this:

http://img253.imageshack.us/img253/1209/subwooferboxdimensions6xa0yo.th.jpg (http://img253.imageshack.us/my.php?image=subwooferboxdimensions6xa0yo.jpg)



bhcarpenter: i dont have the time nor the $$$ to build a sealed and test, then a ported.

i just want to build 1, then get it over w/




and msimon. you are most probably correct. i did not use the correctional factor. so for a box 2.8^3 @ 30hz, my port length should be 28.29" ?


thank you both for help, and fill me in on any other mistakes.

norcalSRTrida
07-10-2005, 08:38 PM
im getting confused.

so if i use 28.29" as my port length, do i go 11.25 back ane the next wall 12.54" long?

davidfre21
07-10-2005, 08:38 PM
bhcarpenter: i dont have the time nor the $$$ to build a sealed and test, then a ported.

i just want to build 1, then get it over w/.
that would only be if u planned to heavily compete like me :)

msimon
07-10-2005, 10:36 PM
bhcarpenter: i dont have the time nor the $$$ to build a sealed and test, then a ported.

i just want to build 1, then get it over w/




and msimon. you are most probably correct. i did not use the correctional factor. so for a box 2.8^3 @ 30hz, my port length should be 28.29" ?


thank you both for help, and fill me in on any other mistakes.

No, I am saying that currently your port length is 28.29". I would just start over as this whole box seems messed up. The port wall and the sides don't add up, .75 + 11.25 + 2 + .75 = 14.75", yet in your drawing it says the side is 14". Also, before driver displacement I get 2.32 ft^3 tuned to 30.5 hz but that is incorrect because your port changes to 1.25" wide after the bend...

norcalSRTrida
07-11-2005, 07:22 PM
No, I am saying that currently your port length is 28.29". I would just start over as this whole box seems messed up. The port wall and the sides don't add up, .75 + 11.25 + 2 + .75 = 14.75", yet in your drawing it says the side is 14". Also, before driver displacement I get 2.32 ft^3 tuned to 30.5 hz but that is incorrect because your port changes to 1.25" wide after the bend...


you are right, that was a mistake that i had made in my drawing, x that out.

my size and length of my box is fine. all i need to find out is the port length for my given measurements.

and you're saying it is 28.29" for it to be tuned to 30hz?


i will re draw my box specs and upload them later tonite, and let me know if they are then correct.

thanks for the help.


mike

norcalSRTrida
07-12-2005, 07:51 PM
bump for any more help.


so if the port length is 28.29" ...then what should be the length of my port walls?


-mike

msimon
07-12-2005, 11:56 PM
bump for any more help.


so if the port length is 28.29" ...then what should be the length of my port walls?


-mike

Did you read my post at all? 28.29" is your CURRENT port length, aka the wrong port length. If you want a box that is 2.8 ft^3 with a port area of 26 in^2, tuned to 30 hz you need a port length of 23.5".

norcalSRTrida
07-13-2005, 12:14 AM
the help was much appreciated msimon. thank you.

one quick question...do i need to adjust that port length due to the box's displacement coming to ~2.6^3 after my sub is installed?

and is the 23.5" the port length? or the length of my port walls?.

as said before, thanks mucho. i can finally start my box building tomorrow or thurs.

msimon
07-13-2005, 12:53 AM
23.5" is what the length should be down the middle of the port. Displacement shouldn't affect the port length, as long after woofer and port displacement your box is 2.8 ft^3, but as it is currently it is much smaller than that.

norcalSRTrida
07-13-2005, 09:33 PM
23.5" is what the length should be down the middle of the port. Displacement shouldn't affect the port length, as long after woofer and port displacement your box is 2.8 ft^3, but as it is currently it is much smaller than that.


thanks for the help man


ill start building it tomorrow or fri and post pics along the way. :veryhapp:

Brian Owens
07-14-2005, 08:59 AM
I cannot believe that only one person has mentioned that the box is not even 2.6-8 ft^3!!!! The port displacement has not been subtracted!!!! That is the gross box volume with only the driver displacement subtracted!!!

30.5 x 13 x 12.5 = 2.86 ft^3.

Take off an approximate 13 x 2.75 x 25 = .52 ft^3 and driver displacement of .18, and the NET volume is only 2.16 ft^3, which requires a much longer port, which reduces the volume even further!!!

Brian