lexx426

Hey, i just scored 4 8" subs, and i would like to build a box to accomodate them all, and maybe an amp. Help me please because this is the first time ever building a box, and i dont know how to do it... I do know that i want a sealed box. (plywood, nailed together, holes for subs, and carpet?) Give me suggestions please

SEmy2K2go

iTrader: (10)

I have 3 JL Audio 8" subs in a single enclosure in my car. Check my webpage for some pics. Depends on the subs you're going with and how you plan to wire them in terms of the box layout.

Robert_J

What kind. Be specific with model numbers.

The best type of box is determined by your subs Theile/Small parameters.

If you want to use plywood, at minimum you need to use baltic birch. It's about $50/sheet from Lowes. Even better is apply plywood. It's also more expensive than birch. MDF is a cheaper alternative but it's heavier than either of the plywoods mentioned above. If you are going to use nails all you need are brad nails to hold the box together while the glue dries. I normally use glue and clamps.

-Robert

lexx426

Sweet! Thats a good design, i like it! The only thing is that only one will be visible due to my rear seat not folding down, but i like the look of the amp on the box. The subs are "Power Acoustik". I believe they are old moddels because i have never seen them before, but they will have to do... (they were free) Does your system kick hard SEmy2K2go? because im not sure if i want to put in 4, or 3...

DJ Kontakt

iTrader: (3)

please, for DJ Kontakt, Use MDF. It is $6 a sheet.

Im about to put 4 8's in my car as well, too bad its a lincoln!

SEmy2K2go

iTrader: (10)

I'm very pleased with the SQ of this setup. I'm not really going for SPL, but it does get pretty loud.

caudio51

Why would you gentlemen prefer to run 3 or 4 eight inch subs compared to two 10s. You would get lowere freq and with a sealed enclosure its still a tight sounding bass. Just want to hear your opinions for the choice....now if you get them for free...well duh why the hell not...but I don't think I would ever go buy 4 eights to put in my car

Robert_J

Not always true. It's all dependent on the subs T/S parameters. Compare the Resonant Engineering RE8 to the Alpine SWE-1041.
Fs = RE is 22.8hz/Alpine is 33hz.
xmax = RE is 12mm/Alpine is 11.7mm
Sd = RE is 195cm2/Alpine is 339cm2

Based on this, the a pair of RE8's will play lower (Fs is lower) and louder (more surface area) than a single Alpine. This is taking into account using sealed boxes to give them the same Qtc. Changing the box will change the Qtc and yeild different results.

-Robert

caudio51

huh I didn't know that thanks for the info

MannyNJ2k2max

iTrader: (3)

Look into Arc v2 8's or IDv38's as well-great drivers

I love the thought of sealed quad 8's with clean 250rms per driver, in a tall cabinet- no much depth utilized in the trunk, plenty of mounting space for amp's behind the box and left over trunk area- superb SQ....Ahhhh to many choices...

lexx426

I love that thought too, but im cheap, and i dont want to buy a box for that, they have to be special made n ****, too much trouble, and money... Now if somebody knows where i can get a quad 8" box for 50-75 dollars, tell me please, cause that would be sweet!

Irish

iTrader: (3)

dont use plywood and nails, MDF and predrill the holes

MannyNJ2k2max

iTrader: (3)

are you kidding? 3 sheets of $7 mdf(2ftx 4ft) and a some screws- i'm sure you have a buddy or relative that can help you if you are not handy

slickrick

iTrader: (12)

why not? do you know something that we all dont know about box building to prevent us from not using the wood glue to hold the box together?

2 Da Max

iTrader: (2)

when i made my first box it was at a slant. well.. that was because the blade was bent

Irish

iTrader: (3)

so your saying plywood and nails is a good way to build a box??

MannyNJ2k2max

iTrader: (3)

hehe....

love the avatar....very happy they're out on dvd now
one of my fav cult classics...

BRAN808

iTrader: (1)

Typically, you'd use particle board or MDF (at least 3/4") I'd prefer MDF since it's denser. Usually you'd predrill the holes, basically to try and prevent the wood from splitting when you screw it together. Then you'd use some sort of wood glue to glue the pieces together. We used to use "Beatsnails". The wood will break before that glue separates. Then, after the box is built, you'd need to apply silicone caulking to seal the inside seams of the box. Then, a lot of times you'd stuff or line the inside of the box with Polyester fiber fill. Keep in mind, that when you design and build your box, this will ultimately determine how good it will sound. If you're unsure, or doubt yourself, have a professional build it. You could have the best subs, but in a improperly designed and built box, you just wasted $$$.
As far as sound wise. Typically 8's give you tighter, more responsive bass. BUT, that's not to say that 8's won't play low. It all has to do with cone area and displacement of air. We did cars with multiple 8's, in properly designed boxes, that could smoke 12's. It's all physics!

lexx426

hmmmmm... so i need to buy mdf, wood glue, screwnails, i have sealant, and i have to buy dynomat spray to put inside, and then im set? my friend has a wood shop i can do all the cuting, and designing in

mendon99

iTrader: (15)

liquid nails works good too (as oppossed to wood glue)

JDogg96

this site contains a lot of useful information on box design http://www.bcae1.com/

slickrick

iTrader: (12)

birch ply and wood glue while clamping until dry is better than mdf and screws. birch is lighter, has slightly less damping, but is much stronger than mdf.

edit: it was pointed out i did not specify baltic birch in another post and people assumed just "plywood". its not the same at all.

Irish

iTrader: (3)

yea its a great movie, its been out on dvd for quite a while... i love that movie


wood glue alone is safe for a box? i wouldnt feel safe with too many watts going to it... learn something new.....is it really safe for say like 1200 watts of power?

slickrick

iTrader: (12)

im sure it is. ask robertj. think about it... the screws just hold the wood in place to let the glue dry. if they did not, then why use glue at all? because 99% of people use some sort of sealant inside the box to keep it air tight anyway so nobody can argue that using the wood glue is for sealing it; its for the construction of it. wood glue is some crazy stuff.

Maxima Dan

As long as you are using a good wood glue and not liquid nails, then you just need to clamp the pieces together until the glue cures. However, if you are using liquid nails you should really use the screws since it never does completely cure and can be softened with heat.

lexx426

hmmmm, what is the stuff i have to buy for the inside of the box other than the sealant for the corners? can you please specify, where i would get it too, thanks.

Robert_J

I'm not the expert. I try to contribute when I have some experience. If you have the clamps, then screws are a complete waste of time. I use Tightbond II wood glue. Sometimes I'll use biscuits to help line up the wood and add a little strength. I use this biscuit joiner.

With straight cuts and glue, you shouldn't have to use anything extra to seal the box. But as a precaution, I also use wood glue to seal up the box. I'll run a bead of it on the inside joints and then smooth it out with my finger. Being liquid, it will seep into any cracks much better than silicone. Also, there's no fumes to worry about.

-Robert

lexx426

One last question before i give it a go... If i want to make a box for 4 subs, am i essentially making 4 separate boxes with 4 sides that are the length of the actual box?
__________
l__l__l__l__l kinda like that???

Subs face here

AscendantMax

iTrader: (7)

yeah, it's better to give each sub its own 'seperate box' instead of sharing one common air space.

MannyNJ2k2max

iTrader: (3)

try making it tall- O O
O O

DJ Kontakt

iTrader: (3)

I am going with 8's because the space I have to work with is only 10 1/2 high at most, and 9 1/2 at the low point