my first box build/s

[dkguitarist]

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]

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]

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]

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]

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]

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]

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]

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]

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. That is a great place to read about how to brace and it also has a bracing calculator if you are lazy.

[dkguitarist]

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]

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]

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]

Yep subtract anything you put inside the enclosure.

[dkguitarist]

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]

one more q. on the divider do i just subtract .75 from one measurement or all 3 again?