Need Box Help!

[Inferno13 10+ year member]

im building a box for a jbl 1241. i know its a little bit old but it's still new/ never been used. the recomendations for the box is 1.25 cft lined with an inch of fiber glass. i just wanted to know what other people have done with this sub as far as the box goes. did you carpet it? or go vinyl? and im lookin to make it sealed cause i want that extra sq. what kind of wood to make thebox out of? any help would be much appreciated. just give me your specs on your box. thanks in advance

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[ss3079 5,000+ posts]

Build the box out of 3/4-1" MDF. Cover it in carpet, vinyl, or leather

 

[Inferno13 10+ year member]

what style of bracing would you recommend. i know that there can never be enough bracing but im not sure whih style to go with. the off center traingles in the corners looked good to me but i would like to know what you would suggest. also for more sond quality with this partcular sub would you go bigger like you would normally? the recommended size is 1.25 for a sealed enclosure. would that be big enough or would you recommend bigger for a sq oriented set up.

 

[Alaxan 5,000+ posts]

Size should be fine at the recomended. Bracing is basically up to you. I rarely ever use bracing anymore just because I only used it for reference or guide. That and it helps while doing the work singlehanded. Typically they take a small amount of airspace away so you have to calculate for that if you are going to be picky with it, but if done properly the box can support itself. Make sure to use screws and not nails unless you use small nails for temp holds while installing screws and I like to use Liquid Nails so i run a bead on each edge before I screw down. If you can break it loose once u got liquid nails on and screws and run another bead of Silicon or Latex down on the inside to ensure the seal you just drove a bull dover over it.

 

[Inferno13 10+ year member]

what is this liquid nail? ive never heard of that. and as far as fixing leaks what about just some caulk? and would you recommend gettin some edead or dynamat to line the inside of the box with? just curious, ive been talkin with ppl about this on other forums.

 

[Alaxan 5,000+ posts]

Unless it is ported there is really no need for Dynamat or Edead. Liquid Nails can be found at about any hardware store it is basically he strongest bonding type of wood glue that you will ever find and works wonders. If you could ever tear up something that has been sealed and connected with liquid nails you would be using a bulldozer or wrecking ball on it. LOL By the way yes still go with a caulk on the interior lines of the box just to be double sure it is sealed off properly. I do this particularly thick and spend a lot of detailed time making sure my boxes are sealed properly however because I utilize two subs in one enclosure space and it makes for an exact vaccum and wave timing of the two. I have found, at least for me, that it makes for a very clean, crisp and accurate bass line.

 

[Inferno13 10+ year member]

great thanks for all your help. just a couple more questions though (sorry i have a lot of them this being my first solo job building a box. ive done it with friends but never on my own.) it doesnt matter what shape of the box correct? but what have you had good experiances with shape wise as far as sq goes? i doubt this makes a difference but im just trying to cover every angle before i start construction. and im assuming that i need to buy wire connections as well so that i can feed my wires through the box. so i guess the only thing left is building the box. thanks for the help.

 

[Alaxan 5,000+ posts]

Hey no problem whatsoever I enjoy building and designing and forming sound with wood and fiberglass and on a couple of occasions plexiglass! The shape does not necessarily matter so much so long as the speaker is not center in a perfect square that just barely surrounds it due to cancelations, but since it is sealed it should not matter so badly. I would even be more than glad to help out with some basic designs if you could give me all of the specs and measurments for the space you are putting it in and the opening for which you are putting it thru to get it in. Specs on the subs would be nice too as far as frequency response curves and air space required. I have been a bit over bored as of late since all of my components are still on order and I am not doing any work on my new install. Boxes and amp racks are already in tho!

 

[Alaxan 5,000+ posts]

It says you are logged on right now so if you get this anytime soon I just wanted to ask you if you had any other forms of chat? I am on yahell and msn and would be glad to talk to you if you would like to ask anything else.

 

[Inferno13 10+ year member]

im on aol. and my sn is the same as here: inferno13. and as for sub specs here they are:

 

[Inferno13 10+ year member]

im on aol. and my sn is the same as here: inferno13. and as for sub specs they are at this website: Click here: http://manuals.harman.com/jbl/car/Boxes and Parameters/GT1241 Enclosure Sheet.pdf

thanks for the help

 

[Alaxan 5,000+ posts]

Ok now what are the dimensions you are looking to set-up in the vehicle? Make sure to measure the space of the entrance to whichever location you are looking ot install to as well. I added you to my aol today too keep an eye out for me as Smileydaman22.

 

[Inferno13 10+ year member]

no prob. i just got home from the ER (busted foot) so i cant measure till tomarrow. you'd think id keep the dimensions handy but i always lose them. anyways, ill measure tomarrow and then post. im thinking something like a half a trapezoid if that makes sense to you. the volume has to equal 1.25 cft so ill work backwards from that for the dimensions. ill just have to think (something im not used to as of late) and then sketch it out. ill let you know tomarrow.

 

[Alaxan 5,000+ posts]

Not a problem at all. Hope your foot feels better. I am on aol right now and not seeing you tho the forum shows your on. Check me out if your around @ Smileydaman22 on aol.

 

[Inferno13 10+ year member]

alright i dont remember it being this hard. im trying to figure out what angle i want the box to be cut at. (the angle of the triangle part of the trapezoid). it's very dificult to figure out how to make this 1.25 cft. i was wondering if you could help. i think that id want the angle to be about 35 to 40 degrees and then figure it out from there. but now im starting to wonder if i should make the enclosure just a rectangle. what shape would give me the best wave response? i think i will just go with the rectangle. well back to the drawing board.