BUILDING A BOX: how?

[Big-Cat 10+ year member]

ok, i decided on a XXX. i'm gonna get a 12, and i took some measurements of my trunk and found out that i've got plenty of room to build a box. however, i don't know the mounting height of a XXX(I couldn't find it on their website) and would i have enough room to mount the sub in the box so it would be firing towards the back of the car?

And another question, my dad says that we'll need something to support the magnet of the subwoofer. Is this true, if so, what could we use?

Also, i want to port the box, but i don't know how to tune a box, can someone please explain how or what i need to do to port the box and tune it to like 33hz?

Thanks

Big Cat

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[mykeys 10+ year member]

First thing.. You do NOT have to support the magnet.. If you are worried about the weight then use and extra piece of MDF on the front side of the box and use 2" screws.

For the hight of the box just make it about 2" taller than the size of the sub you bought..

12"sub box would be 14" tall etc.. As for the best programs to help you figure out the dims Ramos would be your best bet.. I havent used winisd but I know that if you have the T/S parameters then http://kbapps.com can run it for you and tell you the enclosure size needed and the port length with diameter..You could always just email the company and ask ..what size of box and the port dims ..

Mike

 

[ramos 5,000+ posts]

Mykeys is right. You don't need to do anything to support the magnet structure other than mounting the sub in the enclosure. If the height of the enclosure is an issue you can always slant the front of the enclosure.

I would email resonant about the enclosure size. They are real helpful. I myself just ordered a XXX. I can't wait to play with ....//content.invisioncic.com/y282845/emoticons/satan.gif.9c6a335ed7aeeed3ee273e573f1fcaac.gif

 

[Moocow16 10+ year member]

I found this on MTX's website, and it seems to work pretty well. Find out the optimum volume that the box should be in cubic feet. Multipy that number by 1728, and you get the cubic inches. Find the cubed root (not squared root) of that number, and you get the first dimension (which should be the height). Take the first dimension and divide it by 1.62 and you get the second dimension (which should be the depth). Take the first dimension again, and multiply it by 1.62 and you get the third dimension (which should be the length). Now, these are the dimensions for the set volume, and doesn't include the thickness of whatever your using to make the box. For example (and this is to make a rectangular box) if you want a box for a single 12" that needs 1.5 cubic feet of space, you take 1.5 cubic feet, multiply it by 1728 and you get 2592 cubic inches. The cubed root of 2592 cubic inches is 13.74 inches, and that is the height. Take 13.74 and divide it by 1.62 and you get 8.48 inches, and that is the depth. Take 13.74 once again, and multiply it by 1.62 and you get 22.26 inches, and that is the length. This formula works better with 2 or 3 subs, because these dimensions would make a strange looking box (at least i think), but these dimensions work. Now, assuming you're using 3/4 inch MDF, you would add 1.5 to each of these dimensions and you get the total length of the pieces of MDF you need. So the new totals are 15.24(height), 9.98(depth), and 23.76(length). And i have no idea how to properly port a box, sorry. I hope this helps you, or anybody else that reads this.

 

[Big-Cat 10+ year member]

yeah, i think i'm gonna just e-mail the company because i got this program someone else told me to dl, winisd. i don't really understand it at all, and it's all in metric measurements and i don't feel like converting them. Thanks for all the help!

p.s. just a last question, when i make the box i can basically just make a rectangle, cut out the space needed for the XXX, and then cut out the port(s)?

 

[dbhittin 5,000+ posts]

Yep thats What ya do, Its just a gaint sealed box with a port

 

[mykeys 10+ year member]

This is where I go for unit conversions http://www.graniterock.com/calculators/calcconv.htm

Mike

BTW sorry about that I forgot it was metric

 

[Big-Cat 10+ year member]

hey, thanks mkeys. But i e-mailed them and they said a 2.5 cubic box after porting and sub displacement. How can i tell the displacement of a sub? and if i build a 2.5 box after displacement, and i port it does that change the volume of the box?

 

[mykeys 10+ year member]

When you get your sub it should have a spec sheet that gives you the T/S parameters and the driver displacement.. The thing is if the box falls withing +/- 10% of the recommended dims it should be fine, so dont sweat it too much. My guess would be that the sub will fall betweeen .14 and .2cubic feet adding that to your box would be about like adding 1/2" to the width approximately. It would also depend on how you choose to build it. Since I have never and probably will never own a XXX I cant say for sure.

Mike

 

[Big-Cat 10+ year member]

aright everyone thanks for all the help. i've got the dimensions and everything of the box that i need. The tech support from RE sent me pics of the box, so everything is all good. Thanks for walking me through. I'm ordering my sub tomorrow, and you might wanna look for a post from me on how to wire a JBL 1200.1 to a XXX. //content.invisioncic.com/y282845/emoticons/rolleyes.gif.c1fef805e9d1464d377451cd5bc18bfb.gif

Aright, well thanks again.

Big Cat

 

[mykeys 10+ year member]

The power and ground are self explanatory.. the speaker connections are connected internally because its a monoblock amp so just hook it up to the pos and neg..You'll be just fine.

Mike

 

[Big-Cat 10+ year member]

huh?