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dkguitarist
04-12-2006, 09:56 AM
hey guys this will be my first attempt at building a box. i kno it won't be pretty but i'm confident i can do it seeing as how we finally have a table saw (and other various tools). i was wondering if anyone has any or could make any box plans for me? it would be for a set of 12" rl-ps and a set of 12" brahmas. i'll get the max measurements here in a minute. i'm thinking i wanna try sealed first unless i have enough room for a small ported enclosure. lmk what you can do for me. thanks!

Worlddre
04-12-2006, 09:58 AM
if you sealing them you really shouldnt need to pay for plans all you need to know is the necessary internal volume...then just pick dimesnions based on the space you have multiply l x w x h and then divide the answer by 1728 until you reach your desired internal volume

amr952
04-12-2006, 09:59 AM
I could try and help you out some, just post up some max dimensions and the net volume that you would like.

EDIT: I will not charge you seeing as how it is not very difficult, just read the post above and if you still need more help just let me know.

dkguitarist
04-12-2006, 10:01 AM
also, i'm wanting to do a single chamber to give it a bit more volume and account for bracing as well. brb with measurements.

dkguitarist
04-12-2006, 10:04 AM
32.5 x 15.5 x 16.5 are the max dimensions i can do. this is taken from a previous box i had (prefab) and it would BARELY fit in my trunk.

amr952
04-12-2006, 10:12 AM
So what you need to do is take:

32.5 * 15.5 * 16.5 = 8311.875

Then you take 8311.875 / 1728 = 4.81

4.81 is the total volume without accounting for thickness of wood. So now you have to do the formula over while accounting for the thinkness so just subtract 1.5from every dimension if using .75 MDF.

31 * 14 * 15 = 6510

6510 / 1728 = 3.77

3.77 is the Total inside volume of the box not accouning for sub-displacement. So now we need to look up sub displacement. I will look that up and get back to you.

amr952
04-12-2006, 10:16 AM
Ok, the RL-P 12 will take up about .18 cft of space a peice. So what we need to do is take the:

3.77 - 2(.18) = 3.41.

3.41 is the net volume after displacement that the subs would see together. So divide that by 2 and that gives you the volume each sub will see. Which is 1.7.

1.7 sealed I think would be a little much for a RL-p I would try to take it down to 1.2, if you are going to use that Tantrum 1200. So go ahead and try to mess with the dimensions to get your net volume down to 1.2 per sub, maybe even smaller. Then post if up if you want us to check over it.

dkguitarist
04-12-2006, 10:19 AM
how do i account for bracing as well? i wanna do this right the first time and make sure i can do as much as possible to gain experience.

amr952
04-12-2006, 10:24 AM
Sorry, I dont know how I completely left that out. What you do is just measure the braces that you plan to put in and just subtract that from the volume.

Ex. If you are going to use a 2x4x6 peice of wood in the enclosure somewhere you take:

2 * 4 * 6 = 48 Divide 48 / 1728 = .03. That means that brace will take up the .03 cuft in the box. Bracing. (http://www.bcae1.com/spboxnew2.htm) That is a great place to read about how to brace and it also has a bracing calculator if you are lazy.

dkguitarist
04-12-2006, 10:29 AM
so even in a single chamber box they'll each still see 1.7 (minus bracing, etc). but if one goes out for some reason, then the other will see the full 3.41 (minus bracing, etc)?

amr952
04-12-2006, 10:31 AM
Correct, so what I would do is make it dual chamber. But it is up to you :)

EDIT: It will also cause problems with the bad sub moving in and out when the good one hits, unless you take the bad sub out and cover the hole.

dkguitarist
04-12-2006, 10:35 AM
and if i made it dual chamber wouldn't you account for the divider? sorry about all the questions, but i'm new to box building (as if you didn't kno. lol).

ramos
04-12-2006, 10:37 AM
Yep subtract anything you put inside the enclosure. :)

dkguitarist
04-12-2006, 10:41 AM
sweet. thank you. i'll start calculating now and run my figures by you guys when i get it all calculated. you guys are awesome. :-)

dkguitarist
04-12-2006, 10:44 AM
one more q. on the divider do i just subtract .75 from one measurement or all 3 again?

ramos
04-12-2006, 10:59 AM
Subtract it from the total volume .75 (thick) x height x width / 1728 then subtract from the total volume. :)

ramos
04-12-2006, 11:00 AM
Example say your brace is 12 " x 12" x 3/4" = 108 / 1728 = 0.06 cuft if you enclosure was 1 cuft before the divider. It would be .94 after. Any help ? :)

dkguitarist
04-12-2006, 11:08 AM
so without any bracing, accounting for the center divider (.75), it'd be 1.66 each after displacement right?

ramos
04-12-2006, 11:13 AM
Uhh , let's see 3.41cuft internal after basket displacement. so

14 x 15 x .75 = 157.50 / 1728 = 0.09 so 3.41 - 0.09 = 3.32 / 2 = 1.66

So yep 1.66 cuft per side :)

dkguitarist
04-12-2006, 11:16 AM
ok just checking. now time to calculate the bracing. that's gonna be a lil harder for me. (mind you i got off work 3 hrs ago and haven't slept since like yesterday morning).

ramos
04-12-2006, 11:29 AM
mehh, sleeps highly over rated anways :)

dkguitarist
04-12-2006, 11:32 AM
i think i'm making it more complicated than it is esp with trying to figure out the bracing.

ramos
04-12-2006, 11:35 AM
Pretty simple really . Now that you have the two chambers. Make identical bracing for each side. Figure the volume, then subtract it . :)

dkguitarist
04-12-2006, 11:39 AM
common sense would tell me in order to calculate for each chamber seperate, i'd just half the internal measurements?

ramos
04-12-2006, 11:43 AM
Your confusing yourself. Don't think of it as a whole anymore. Think of it as two identical enclosures. What you do to one, do to the other. you have two 1.66cuft enclosures. Figure bracing for one, then do the exact same thing to the other. :)

dkguitarist
04-12-2006, 11:50 AM
ok, so i got (.75 x7 x7.5/1728= 2(.02)=.04

1.66-.04=1.62

ramos
04-12-2006, 11:53 AM
There ya go, same thing for the other side. Don't think so hard my brother :)

dkguitarist
04-12-2006, 11:57 AM
thank you so much ramos and amr92. i appreciate the friendly help with so many newb questions. now just gotta make it a lil smaller. that's exactly why i didn't wanna attempt ported just yet. ;)

ramos
04-12-2006, 12:12 PM
Yeah man.
What do you need smaller external or internal ? :)

dkguitarist
04-12-2006, 12:18 PM
directly off the ss website: "0.75 - 1.5 cu ft, with the general consensus being that 1.0 - 1.2 cu ft net volume is ideal for a solid balance of low frequency extension and overall output"

dkguitarist
04-12-2006, 12:19 PM
so if anything, i need external a tab bit smaller. unless internally i can acheive at least that 1.5

ramos
04-12-2006, 12:26 PM
You can with you cuurent configuration by adding more bracing. But since you haven't built it yet. Why not just make it a little smaller from the get go. 30 x 14 x 14 internal will get you really close. Might want to go 31 x 14 x 15 internal so there is a little room for bracing :)

dkguitarist
04-12-2006, 12:33 PM
You can with you cuurent configuration by adding more bracing. But since you haven't built it yet. Why not just make it a little smaller from the get go. 30 x 14 x 14 internal will get you really close. Might want to go 31 x 14 x 15 internal so there is a little room for bracing :)

with the 31x14x15 internal and the divider and the bracing, it's 1.62^3 each.
or are you saying increase the bracing?

amr952
04-12-2006, 12:36 PM
Yes, you could increse the bracing you use. Or you could just shrink the dimensions and reacalculate until you get the size that you are shooting for. Either one will work, but like said above it would be easier to just make the box smaller since you have not built it yet.

dkguitarist
04-12-2006, 12:38 PM
thank you. i'll probly have a box plan for each set of subs made up here in a few minutes. thank you guys so much. you're wonderful.

amr952
04-12-2006, 12:40 PM
No problem, just post it up. Sorry I missed some of your questions, I was gone for a while but it looks like you got all the answers you needed. I am in and out today. Trying to clean up my yard.

Good luck with your plans. :)

dkguitarist
04-12-2006, 12:49 PM
ok, so the plan for the 12" rl-ps sealed will be 31.5 x 16.5 x 15.5 externally. 1 inch shorter than my max dimensions i posted. this is all including the divider/bracing/displacement. it comes out to 1.52^3 each. maybe use some polyfill to take off that .02^3

give me a few to work on the box for the 12" brahmas.

amr952
04-12-2006, 12:51 PM
ok, so the plan for the 12" rl-ps sealed will be 31.5 x 16.5 x 15.5 externally. 1 inch shorter than my max dimensions i posted. this is all including the divider/bracing/displacement. it comes out to 1.52^3 each. maybe use some polyfill to take off that .02^3

give me a few to work on the box for the 12" brahmas.

Are you sure that you posted the dimensions correct. That will come out to like 2.3 per sub before displacement and bracing. That is alot of bracing.

Are you planning on using that Tantrum on the RL-P's?

amr952
04-12-2006, 12:55 PM
Nevermind, stupid question. I was reading the specs wrong. Looks like you will be giving each about 700 watts. That will sound pretty good in 1.4-1.5. So you are perfect. Just check those dimensions you put down they dont sound good.

dkguitarist
04-12-2006, 12:59 PM
the dimensions i remeasured. it is all correct. 1 inch off the length. bracing will be 7" x 7.5" x 3/4"

amr952
04-12-2006, 01:00 PM
I just cant read today lol. It says externally. That will be perfect, as long as your bracing brings it down to 1.52.

Sorry about that. :crazy:

dkguitarist
04-12-2006, 01:02 PM
i didn't have it written down cuz it was 1.62 each. so i just knocked 1 inch off the length and use the same calculations for everything else and it came out to 1.52. did it twice to make sure.

dkguitarist
04-12-2006, 01:03 PM
as for the brahmas, using the same calculations, i came up with 1.61 each using the 31x15x14. i think i need to change something.

amr952
04-12-2006, 01:06 PM
Something is still not right, It looks like after bracing it will be about 1.62

31.5 * 16.5 * 15.5

subtract 1.5

30 * 15 * 14 = 6300 / 1728 = 3.64 total

3.64 / 2 = 1.82

After sub displacement

1.82 - .18 = 1.64

After Bracing

7 * 7.5 * .75 = 39.38 / 1728 = .03

1.64 - .03 = 1.61

Did I miss something along the lines?

dkguitarist
04-12-2006, 01:08 PM
Something is still not right, It looks like after bracing it will be about 1.62

31.5 * 16.5 * 15.5

subtract 1.5

30 * 15 * 14 = 6300 / 1728 = 3.64 total

3.64 / 2 = 1.82

After sub displacement

1.82 - .18 = 1.64

After Bracing

7 * 7.5 * .75 = 39.38 / 1728 = .03

1.64 - .03 = 1.61

Did I miss something along the lines?

yes. i rounded up the decimals. my bad. newbish mistake. :rolleyes:

amr952
04-12-2006, 01:09 PM
If you make the inside dimensions to be 28 * 15 * 14. That will work out perfect 1.49. Give that a try.

amr952
04-12-2006, 01:09 PM
yes. i rounded up the decimals. my bad. newbish mistake. :rolleyes:

Easy mistake, no big deal.

Just dont ever do it again :furious:

j/k

dkguitarist
04-12-2006, 01:12 PM
edit, i keep ****ing up

amr952
04-12-2006, 01:14 PM
You will get it, just take your time to make sure you get it right before you build. :)

dkguitarist
04-12-2006, 01:15 PM
i keep getting 1.39

amr952
04-12-2006, 01:16 PM
Well, I could be wrong so let me check real quick.

amr952
04-12-2006, 01:18 PM
28 * 15 * 14 = 5880 / 1728 = 3.4

3.4 / 2 = 1.7

1.7 - .18 = 1.52

7 * 7.5 * .75 = 39.375 / 1728 = .03

1.52 - .03 = 1.49

That is what I get. Inside Dimensions.

dkguitarist
04-12-2006, 01:20 PM
you left out some things.

28*15*14=5880/1728=3.40

3.40-.36=3.04/2=1.52

1.52-.09=1.43-.04=1.39

amr952
04-12-2006, 01:21 PM
you left out some things.

28*15*14=5880/1728=3.40

3.40-.36=3.04/2=1.52

1.52-.09=1.43-.04=1.39

Where does the .36 come from?

dkguitarist
04-12-2006, 01:22 PM
Where does the .36 come from?

displacement. did it differently than you. got the same 1.52. but you left out the bracing and divider..

amr952
04-12-2006, 01:23 PM
Oh, I did not realize that you decided on making 2 chambers. I read through really fast, guess I missed it.

dkguitarist
04-12-2006, 01:24 PM
i have blown 4-5 subs before....don't wanna risk one taking the other with it.

amr952
04-12-2006, 01:25 PM
So if you do:

29*15*14=6090/1728=3.52

3.52-.36=3.16/2=1.58

1.58-.09=1.49-.04=1.45

That looks pretty good. You could do 29.5 if you want that little extra to reach 1.5. Sorry about missing the divider and confusing you. Looks like we have it figured out now.

dkguitarist
04-12-2006, 01:27 PM
So if you do:

29*15*14=6090/1728=3.52

3.52-.36=3.16/2=1.58

1.58-.09=1.49-.04=1.45

That looks pretty good. You could do 29.5 if you want that little extra to reach 1.5. Sorry about missing the divider and confusing you. Looks like we have it figured out now.

thank you sir. :cool: now can you go back and look at my brahma box plan? think i need to change something with that. i think it's on page 2..;)

amr952
04-12-2006, 01:29 PM
thank you sir. :cool: now can you go back and look at my brahma box plan? think i need to change something with that. i think it's on page 2..;)

I sure can. lol we have 4 pages just for 2 boxes.

I have 2 questions though, what is the displacement of the brahama, and how much space would you like to give them.

Sorry I dont know much about those.

dkguitarist
04-12-2006, 01:32 PM
it is right around .15. i was told that 1.75 would be plenty of space sealed per driver. i think 1.8 max is what adire recommends. but i don't think i can achieve that.

amr952
04-12-2006, 01:36 PM
31 * 15 * 14 = 6510 / 1728 = 3.77

3.77 - .3 = 3.47 / 2 = 1.73

1.73 - .09 - .04 = 1.61

Looks like that will work out pretty good right within Adires specs.

dkguitarist
04-12-2006, 01:37 PM
any way to make it a bit bigger? maybe .1 cube bigger?

amr952
04-12-2006, 01:40 PM
Well to make it bigger we would have to increase one of the dimensions. So far the outside dimensions are going to be at your max 32.5 * 16.5 * 15.5.

31 * 15 * 14 + 1.5 to all sides

32.5 * 16.5 * 15.5

Which dimension could you give a little more on?

dkguitarist
04-12-2006, 01:43 PM
i can use the 32.5 x 16.5 x 15.5 perfectly. i have a current prefab box (blew my L7's in) and the specs were taken from it. maybe take 1/4". as i couldn't see too well. but i had maybe 1/4" to spare depthwise.

amr952
04-12-2006, 01:46 PM
Well seeing as how the box is 1.6 cuft with your max dimensions you are going to have to go out and measure your car to see if we can squeeze some more out of it.

ramos
04-12-2006, 01:47 PM
ok, so the plan for the 12" rl-ps sealed will be 31.5 x 16.5 x 15.5 externally. 1 inch shorter than my max dimensions i posted. this is all including the divider/bracing/displacement. it comes out to 1.52^3 each. maybe use some polyfill to take off that .02^3

give me a few to work on the box for the 12" brahmas.


ixnay on the polyfill my brother. Polyfill makes the enclosure seem larger. It's gonna be sealed I wouldn't worry about .02 cuft. You won't notice it. :)

dkguitarist
04-12-2006, 01:50 PM
ixnay on the polyfill my brother. Polyfill makes the enclosure seem larger. It's gonna be sealed I wouldn't worry about .02 cuft. You won't notice it. :)

yeah. after amr92 gave me his dimensions, i wasn't worried about it. i'll go either way with it then.



as for the measurements i'll be right back with the true dimensions.

amr952
04-12-2006, 01:53 PM
Well, I am taking my fiance to lunch so if ramos cant help you on your final dimensions for the Brama I will as soon as I get back. If you need any more help just post in here or pm me I will be glad to help. Have fun.

Remeber Measure 4 times cut once. :)

dkguitarist
04-12-2006, 01:55 PM
thank you for all your help. you are truly appreciated. and you are too ramos.

dkguitarist
04-12-2006, 02:08 PM
so the measurements are all 1/4"

dkguitarist
04-12-2006, 02:32 PM
so i redid all my calculations.

for the RL-P's:

30.75*14.75*13.75=6236.48/1728=3.60-.36(displacement of both drivers)=3.24/2=1.62-.13(divider and bracing values combined)=1.49^3

for the Brahma's:

30.75*15.25*14.25=6791.01/1728=3.92-.3(displacement of both drivers)=3.62/2=1.81-.13(divider and bracing values combined)=1.68

am i correct? does anyone see any problems/have any suggestions?

ramos
04-12-2006, 02:35 PM
Looks right :)

dkguitarist
04-12-2006, 02:38 PM
thank you ramos. and amr92. you guys are wonderful. i learn something new everday. hehe. i'm ecstatic now. the rl-ps should be coming the end of the week, and the brahmas in 2 weeks or so. thanks again!

ramos
04-12-2006, 02:50 PM
Yeah man, have you checked out http://www.bcae1.com/ lots of good stuff there :)

amr952
04-12-2006, 02:59 PM
Yeah man, have you checked out http://www.bcae1.com/ lots of good stuff there :)

x2 on that

I read that and I learned so much, just look at a few pages each day.

Good luck with the box let us know if you need anything else.