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violator5spd
01-15-2003, 08:47 PM
i'm going to build a sealed box for my re se's in a week or 2, it should be about 4cu.ft with a divider in the center for added stability. i'll be using a jbl 600.1 running at 1ohm. my question is keeping the box together...would liquid nails & 2inch wood screw every 6in or so be enough? last thing i wanna do is blow the box a little loose. my friends dad was talking about mounting small blocks on the inside to screw into from the outside, but i dont really wanna have to do that unless it's necessary to keep my box together. i dont think it's needed with only 600w, but correct me if i'm wrong cuz i dont' wanna be wrong later...:rolleyes:

thanks

Randy Savage
01-15-2003, 08:48 PM
Liquid nails and 2" nails should be just fine.

violator5spd
01-15-2003, 08:50 PM
Originally posted by snova031
Liquid nails and 2" nails should be just fine.

ok, thanks...but wouldn't screws be more effective than nails?

jbl_marshall21
01-15-2003, 08:57 PM
use screws. nails might pop out after time

Randy Savage
01-15-2003, 08:58 PM
Originally posted by violator5spd
ok, thanks...but wouldn't screws be more effective than nails? Oops...meant screws:D

violator5spd
01-15-2003, 09:01 PM
Originally posted by snova031
Oops...meant screws:D

alright thats what i was thinking...thanks man

evo2k3
01-15-2003, 09:02 PM
liquide nails is fine...but wood glue works well to and its a bit less messy. Dont use 2 inch screws, that just increases your changes of spliting the wood and requires long pilot holes....use 1.5 inch cource threaded drywall screws.

violator5spd
01-15-2003, 09:15 PM
should my pilot holes be the whole length of the screws?

evo2k3
01-15-2003, 09:26 PM
Originally posted by violator5spd
should my pilot holes be the whole length of the screws?

dont stress out about that...but yeah they should be as deep as the screw is going to go in....so if your using 1.5" and 3/4" mdf they should be drilled about 3/4" in....but like i said dont make a big deal out of drilling them.

geonn
01-15-2003, 10:15 PM
i usually use woodglue not liguid nails and drywall screws that are 1 5/8 they work pretty good and the only drilling i do is on the faces with screws and i just use a countersink bit so the heads of the screws are totally in the wood and not stickin out at all and then on the inside of the box i use caulk or silicone to seal it up real good

evo2k3
01-16-2003, 12:58 AM
i countersink as well, but only for appearence when i vinal or carpet it. Clear through the first peice, pilot the second...thats the best way to do it, dont do it any other way...end of story.

n2ma
01-16-2003, 02:27 PM
I have built countless boxes with 2" drywall screws with liquid nails. I started out using wood glue but found that liquid nails ( or sub floor adhesive) works better. The wood glue is great for grained wood. Using MDF does not have many pores for the wood glue to bond to. Also the wood glue is very stiff and cures very hard. With liquid nails it bonds, and seals at the same time. With the intense stress of SPL In a box you want all the bond you can get. Adding some bracing in boxes over 4 cu ft is always a good idea. I always over build each box.
As far as using 2" screws You won't have to worry about cracking the mdf if you counter sink and use a bit (like a #6) to pre drill. Then use a #6 screws. You can make sure by holding the bit next the screw. You should have a bit just small enough to see just the threads of the screw.
For really high spl boxes, I have found that using a threaded Rod in the the middle helps keep the flex down with out giving up to much airspace.

evo2k3
01-16-2003, 03:07 PM
thanks for the recap....lol

violator5spd
01-16-2003, 11:08 PM
just wondering, would putting a few layers of fiberglass inside the back of the box have any effect on the sound? my dads friend mentioned it but it didnt make any sense to me...?

paikiah
01-16-2003, 11:16 PM
Originally posted by violator5spd
just wondering, would putting a few layers of fiberglass inside the back of the box have any effect on the sound? my dads friend mentioned it but it didnt make any sense to me...?

MDF by nature, is porous...thereofre, some people prefer to seal it 100%...hence, the fiberglass...

but a lot of people don't use it... maybe ahrdcore box builders, for their own boxes.. I certainly didn't, just left it as it was, and it's not too bad...

check out my member gallery pics, you'll see what I mean...

evo2k3
01-17-2003, 02:21 AM
look...i am at about the upper bounds of my knowledge hear, but ill stick the idea out anyways. How is mfd porus by nature....think of how it is made, basicly compresed saw dust and glue/epoxy. I really dont think mdf will leak air by nature. Plus fiberglass is epoxy, how does adding more of it make it more sealed? just a question, thats what makes sence to be. I mean i have glassed seems where the cap was a touch to big for silcon and it works great for the seams, but the only thing i can see it doing is stifening the box up a bit and making it look nice. just my 0.02.

paikiah
01-17-2003, 02:31 AM
Originally posted by evo2k3
look...i am at about the upper bounds of my knowledge hear, but ill stick the idea out anyways. How is mfd porus by nature....think of how it is made, basicly compresed saw dust and glue/epoxy. I really dont think mdf will leak air by nature. Plus fiberglass is epoxy, how does adding more of it make it more sealed? just a question, thats what makes sence to be. I mean i have glassed seems where the cap was a touch to big for silcon and it works great for the seams, but the only thing i can see it doing is stifening the box up a bit and making it look nice. just my 0.02.

Well, lemme change what I said...

I HEARD MDF was porous, so I was advised to do something either in the inside or outside, if my box were to handle great amounts of power... but I'm no professional...

glass can't be porous, right? that's why I'm saying maybe that's why YOu were advised to use fiberglass inside...:) afterall, a lot of canoes, and the jetski hulls are made of fiberglass...it's not porous...;)

if the walls of the box leaks, you can apply a thin fiberglass layer to prevent any possible leakage, that's what I think it is....:)

evo2k3
01-17-2003, 01:39 PM
by point is just that I really think the seems are going to leak far before you are able to puch air through mdf....because is a part fiberglass.

Savant
01-17-2003, 02:25 PM
Originally posted by evo2k3
look...i am at about the upper bounds of my knowledge hear, but ill stick the idea out anyways. How is mfd porus by nature....think of how it is made, basicly compresed saw dust and glue/epoxy. I really dont think mdf will leak air by nature. Plus fiberglass is epoxy, how does adding more of it make it more sealed? just a question, thats what makes sence to be. I mean i have glassed seems where the cap was a touch to big for silcon and it works great for the seams, but the only thing i can see it doing is stifening the box up a bit and making it look nice. just my 0.02.

Porus doesn't mean 'leak air'.. it means little cavaties on the surface (more or less).. your skin is porus but your lungs work because your chest is a vaccume inside.. if porus meant leak, we wouldn't be able to breath..

That said, fiberglass + resin is very low on the porus scale.. you can put water on it and it won't seep in... MDF will **** up water even though there is glue/epoxy/whathaveyou holding it together.. the 'bulk' of the material is wood.. with fiberglass, the bulk is glass and solid plastic..

Putting 'fiberglass' in a box (meaning layering a buildup with resin etc).. Not sure you will gain anything there.. it might have a higher resonance (reflect sound better) than the MDF and prevent some of the sound from getting absorbed by the wood (it might muddy the sound a bit, the glass might help keep it crisp).. but I doubt you would really notice much difference.. Putting Fiberglass Insulation in the box.. now that's a totally different matter.. that's like putting in fill (that's what it is actually, just not called 'fill'..).. I forget exactly how that works.. I think fill is supposed to make the woffer think there is 'more' volume in the box, which is counter intuitive since you filled up space.. I just know my buddy (way back when) would put insulation (filler) in his enclosures once in a while.. not sure it really made a difference.. Perhaps that's what was meant by the suggestion to you?

ramos
01-17-2003, 03:08 PM
Yes MDF is porous. Using your own example think about how it's made. It is basically wood particles compressed together under extreme preasure. Then soaked in a formaldahyde glue. That's pretty much all there is to the process of manufacturing it. No special care is taken to make sure the particles are perfectly aligned so that it is airtight. How could it not be porous ? For an even better example look at an edge after you cut it. ;)

If you make your cuts straight and clean. Then really all you need to use is a good urethane glue to hold the enclosure together. All I use is gorilla urethane glue and 1 1/4 brads. . I can build a box using nothing but glue. And I would bet you North America tat yo will break the MDF before The glue lets go. :)

ramos
01-17-2003, 03:11 PM
Now if your talking about putting actual Fiberglass cloth or mat it will greatly increase the strength of the enclosure. But it really wouldn't make any audible difference. If your talking about just brushing some resin on the inside. You won't gain any strength. But you will seal it up pretty well. You might actually gain a few db's on a meter. But I still doubt there would be any audible difference. :)

Savant
01-17-2003, 03:30 PM
Originally posted by ramos
Yes MDF is porous. Using your own example think about how it's made. It is basically wood particles compressed together under extreme preasure. Then soaked in a formaldahyde glue. That's pretty much all there is to the process of manufacturing it. No special care is taken to make sure the particles are perfectly aligned so that it is airtight. How could it not be porous ? For an even better example look at an edge after you cut it. ;)

If you make your cuts straight and clean. Then really all you need to use is a good urethane glue to hold the enclosure together. All I use is gorilla urethane glue and 1 1/4 brads. . I can build a box using nothing but glue. And I would bet you North America tat yo will break the MDF before The glue lets go. :)

Hmm.. so I really don't need 27 screws on a 12x12 top-plate if I'm using liquid nails? I mean, does the glue really cure that hard that you don't get any usefulness from the screws?..

*grumbles about buying a second box of screws and adding 50 lbs of weight to each box in threaded madness*

evo2k3
01-17-2003, 03:58 PM
Originally posted by Savant
Hmm.. so I really don't need 27 screws on a 12x12 top-plate if I'm using liquid nails? I mean, does the glue really cure that hard that you don't get any usefulness from the screws?..

*grumbles about buying a second box of screws and adding 50 lbs of weight to each box in threaded madness*

kind of the same thing i told you in the other thread....lol....you need screws or clamps to hold the glue as it cures....I suppose brads would work well if you had a air gun for it, but putting them in by hand is probably hard that usuing a screw gun (a more common home workshop tool) to run screws into pilots. When you use brads, do you have any trouble with the would splitting? I also think it is safe to say that we all agree air is not going to leak through the side of a box. and the fiber glass can add strength and appearence...that pretty much some it up?

nswartley
01-17-2003, 04:08 PM
actually MDF stands for 'medium density fiberglass': it is not just wood

ramos
01-17-2003, 04:12 PM
Nope no splitting what so ever. And you are correct. The screws or brads in my case. Are basically there to hold the enclosure together until it dries. Of course you leave them in. Every little bit helps. But believe me the brunt of the blow is being taken by the glue. Remember though. When your using MDF. The best adhesive you could possibly use is a urethane wood glue. There are several different brands availiable at home depot, Lowes or any place like that. :)


And

M edium
D ensity
F iberboard

There is also

LDF - Low Density Fiberboard
HDF - High Density Fiberboard

and various light weight versions of each. :)

Savant
01-17-2003, 04:39 PM
Originally posted by nswartley
actually MDF stands for 'medium density fiberglass': it is not just wood

Nope.. medium density fiberboard.. like particleboard, only it's not made with 'particles', it's made with 'fibers'.. smaller chunks, packs better, denser, less brittle, etc etc etc.. I'll bet dollars to pennies that there is no glass in MDF at all..

Savant
01-17-2003, 04:40 PM
Originally posted by evo2k3
kind of the same thing i told you in the other thread....lol....you need screws or clamps to hold the glue as it cures....

But you made fun of me so I discounted everything you said :p

And, I like to get confirmation on most things I hear, so don't be offended ;)

evo2k3
01-17-2003, 05:17 PM
Originally posted by ramos

M edium
D ensity
F iberboard

There is also

LDF - Low Density Fiberboard
HDF - High Density Fiberboard

and various light weight versions of each. :)

yup yup....not fiberglass...that doesn't even make sence...think about....and no offense takin savat....just givin you a hard time :) .

nswartley
01-17-2003, 05:38 PM
i think its safe to say i got shot down :(

violator5spd
01-17-2003, 07:59 PM
what diameter hole do i need to cut out for my re se's?? i know its less than 12"...maybe something closer to 11?

evo2k3
01-17-2003, 08:40 PM
Originally posted by violator5spd
what diameter hole do i need to cut out for my re se's?? i know its less than 12"...maybe something closer to 11?

the manufacture should have specs for this with the subs.

paikiah
01-17-2003, 08:42 PM
Originally posted by violator5spd
what diameter hole do i need to cut out for my re se's?? i know its less than 12"...maybe something closer to 11?

THe cutout diameter should be given in your manual...

but if you've got a hole cutter (look at my member gallery pics, I used the hole cutter and it cuts REALLY clean...very cheap too~), then just use the blades to measure how big a hole you really need, no need for minute adjusting..just drill and cut away~

violator5spd
01-18-2003, 02:09 AM
no manual or specs came with the subs...nothing at all came, except the subs...the only specs i can find on them are these

12SE
Re 5.7
Fs 31.2
Qms 5.18
Qes .63
Qts .56
Vas 48.9 l
Sd 480 cm^2
Xmax 16mm
600 Watts RMS
Sealed: .75 cuft for SQl applications.
Ported: 2 cuft on up(tuned to 35Hz for daily apps)

sooo.....yea?

paikiah
01-18-2003, 04:45 AM
Ok, then here's another solution...

you could either

1. use a thread to go around the circle and then measure the length of the thread in order to get the diameter...voila~

2. go to your stationery shop and buy a flexible ruler...might be a bit hard to work with since it'll contain a flexible metal and might try to keep on sticking to your magnet...

Savant
01-18-2003, 05:04 AM
Or, you could run a string, stick, somethingthatgivesyouradius from the center of the sub to the edge of the lip on the mounting surface... then transfer that to our box.. You might have to guess as to the 'center' of the woofer, but you should be able to come within a 1/16" or so.. at least, I think you can...just depends on you....

nswartley
01-18-2003, 01:30 PM
start out with a smaller cutout diameter, and then keep making bigger as necessary. DEFINITELY dont make it too big

violator5spd
01-18-2003, 09:30 PM
Originally posted by nswartley
start out with a smaller cutout diameter, and then keep making bigger as necessary. DEFINITELY dont make it too big

good strategy ;)

evo2k3
01-18-2003, 10:43 PM
how about just messureing man...not that big of a deal....and if your going to do the trial and error method suggested....get some 1/8" hard board and get your size done in there. Pretty much no matter how you cut your cirles (free hand jig saw, circle tempate on your router, roto zip, ect) there is no good way to cut just a little bit more off since the middle part that had the center is gone, thats why starting small and getting bigger, is not a great method, the best method "messure twice, cut once " :)

nswartley
01-19-2003, 01:56 AM
get the circumference of the screwholes, then circumference=diameter times pi

terifi
01-19-2003, 06:09 PM
so woodglue will work to seal a box?, do i NEED to go over the inside seams with silicone, i already put my sub in, but if its gonna make a big difference, i would take the sub back out, and seal it with the silicone.

what is the result if your box is "not quite sealed"

nswartley
01-19-2003, 06:16 PM
Originally posted by terifi
so woodglue will work to seal a box?, do i NEED to go over the inside seams with silicone, i already put my sub in, but if its gonna make a big difference, i would take the sub back out, and seal it with the silicone.

what is the result if your box is "not quite sealed"

i would just do it anyways. definitely couldnt hurt, but it could only make it perform better

terifi
01-19-2003, 06:28 PM
yeah, im just wondering if its worth the effort, when i got the wire from the terminal to the driver, it was just...well needless to say, too short, and it was very hard to hook the sub up, but i guess i may as well go head, hey then i can answer my own question, "is it really worth it" :)

nswartley
01-19-2003, 06:29 PM
Originally posted by terifi
yeah, im just wondering if its worth the effort, when i got the wire from the terminal to the driver, it was just...well needless to say, too short, and it was very hard to hook the sub up, but i guess i may as well go head, hey then i can answer my own question, "is it really worth it" :)

heh :D

evo2k3
01-19-2003, 07:06 PM
yes...it is definitley really worth it...wood glue doesn't seal very well.

violator5spd
01-19-2003, 10:10 PM
Originally posted by evo2k3
yes...it is definitley really worth it...wood glue doesn't seal very well.

yep...wood glue isn't for sealing, just helping to hold it together, you definitely need to seal the inside of the box, if there is a leak it will sound like ****...kinda sounds boomy

paikiah
01-19-2003, 10:21 PM
a leaky box might also sound as if it's farting...;)

violator5spd
01-19-2003, 10:23 PM
Originally posted by paikiah
a leaky box might also sound as if it's farting...;)

**** you!...i'm jealous, you're so good with words...;)

paikiah
01-19-2003, 10:24 PM
Originally posted by violator5spd
**** you!...i'm jealous, you're so good with words...;)


hahahahha....I do with what I have~:D

HectorZ
01-21-2003, 01:53 AM
im gonna go with the www.jlaudio.com specs for my 10W-7 box


3/4 mdf on sides and 1" up front...

urethane wood glue and 2" dry wall screws

six pack of beer

anything else I need to know ?

paikiah
01-21-2003, 07:25 AM
Originally posted by HectorZ
im gonna go with the www.jlaudio.com specs for my 10W-7 box


3/4 mdf on sides and 1" up front...

urethane wood glue and 2" dry wall screws

six pack of beer

anything else I need to know ?

Yeah, silicone... just in case of inperfections...;)

They also forgot to tell you that should you be using screws, you should drill the holes first and sink it if you want to carpet it... oh, and use a 90degree ruler so hat our walls and the floor is accurately opposed.

ramos
01-24-2003, 08:01 AM
Originally posted by paikiah
oh, and use a 90degree ruler so hat our walls and the floor is accurately opposed.



If I may ask, why ?Shape of the enclosure makes no difference. Your enclosure is physicaly too small to have to worry about standing waves. Unless of course your box has dimensions 10-20 ft. :)

evo2k3
01-24-2003, 09:25 AM
Originally posted by ramos
If I may ask, why ?Shape of the enclosure makes no difference. Your enclosure is physicaly too small to have to worry about standing waves. Unless of course your box has dimensions 10-20 ft. :)

if your cuts are beveled at 90 degrees but they get put together at 85 degrees, the other side compensates, it is 95 dgrees and you loose a considerable amount of structural integrety. Whenever you build anything that is suppose to be sqaure, you should build it square.

paikiah
01-24-2003, 11:53 PM
Originally posted by evo2k3
if your cuts are beveled at 90 degrees but they get put together at 85 degrees, the other side compensates, it is 95 dgrees and you loose a considerable amount of structural integrety. Whenever you build anything that is suppose to be sqaure, you should build it square.

Ah, thank you so much for that~:D

You'll need to align the walls so that it the top (or base) meets squarely with the walls.. if ou put 5degrees off the walls and try to screw it, you would probably see a gap about 2~3mm, and that ain't gonna do you no good, unless you're planning on putting it on the sides and exerting an enormous amount of pressure to make it meet, just cause you didn't use the 90degree ruler...and by then, there's gonna be so much of pressure on the screws of the walls or top(don't tell me you're just gonna use woodglue and hold the pressure down till the dries).. if you build it for a powerful sub, then it might just blow...:p

ramos
01-30-2003, 11:24 AM
Originally posted by evo2k3
if your cuts are beveled at 90 degrees but they get put together at 85 degrees, the other side compensates, it is 95 dgrees and you loose a considerable amount of structural integrety. Whenever you build anything that is suppose to be sqaure, you should build it square.



Okay I see. I thought you were saying not build it as a perfect square. Yes I do agree. The straighter your cuts, the less silicon you need to use. :)

ryan_feine
02-17-2003, 03:16 PM
Originally posted by violator5spd
what diameter hole do i need to cut out for my re se's?? i know its less than 12"...maybe something closer to 11?
the size of the whole should be under the specs in the manual

n2ma
02-17-2003, 06:55 PM
1.) invest in a 12 pack and some friends to hold the box together wile work on it.
2.) invest in some bar clamps. Bar clamps don't break your tools when they drink all the beer.

violator5spd
02-17-2003, 07:01 PM
Originally posted by ryan_feine
the size of the whole should be under the specs in the manual

Maybe, but RE doesn't send out manuals when you purchase their products. This is an old post though, I can figure out the size easily, thanks.