2 12" Speaker split box

[Still learning]

I'm planning on making a box for two 12s, this never came to mind till this morning, but i have seen boxs for two subs that have a chunk of wood splitting the box into, what is two boxs put together. The box volume i have to make is 1.3 cubic feet for each sub, what my question was; should i make the box 2.6 cubic feet and call it good? or should i make it split in half to make two boxs @ 1.3 cubic feet each? Also i would think that the two boxs split in half would be usefull for stero sound, you know have on sub hooked up to one channel and the other hooked up to the other cahnnel(assuming you have a two way stero amp) that way the wind paths wouldent mix up and come out with some weird bass, is this correct?

[hellohello]

the proper way is to have 2 seperate 1.3 cu ft enclosures... but that seems kinda huge for a 12".. what sub are u using? The idea of having 2 seperate chambers is that the air sealed inside forms a vacuum, not like a hoover, but as in the meat u get at the supermarket... u know sealed airtight. With the proper amount of air volume inside the box, the suspension of the speaker will have to "fight" to go beyond its limits, like the sealed meat i mentioned, they seal it so the meat cant escape the packaging, despite what the label may say :p

[neomagus00]

there are two advantages to putting that center divider in: 1) a stronger box and 2) if one sub dies, you still get some bass (and you don't destroy sub #2)... the disadvantage is a slightly larger box that is slightly heavier... the sound won't change a bit from one to the next, so no worries there... and don't bother running them in stereo, it won't do anything (for the VAST majority of setups, and even in that little minority, the usefulness is questionable)...

[Still learning]

Ok so, how is the box bigger when i have the two 12s in it than if i was to have two seperate boxs? im making the box with angled front faces, but i am using the formula:--- Area of the base, multiplyed by the height, to get the cubic volume in inches, then i have to do the whole 144/12 thing. to get the cubic feet, so if i make the box for the two 12s the exact amount of vol i need (1.3 cubic feet) then it shouldent be any bigger right? it will be just like putting the two boxs together yea? I thinkl im going to go with the diviver thing, limite space isnt really an issue, the box is going into the back of a 1993 eagle talon, so it should be fine.

With the air thing, ?????

P.S>- what happens when you make the volume to big? or to small? Lets say that i was to make the box for the 2 12s and i made it 3.0 cubic ft, what would happen then?

thanks

[neomagus00]

the box is wider by 3/4 inch, if you're using 3/4" MDF (reccommended) for the divider... and yes, with the divider, it's like two boxes that share a wall... air thing??... and if you make the box too big, you gain low bass extension in exchange for transient response (it sounds deeper but sloppier/boomier)... if the box is too small, you get a higher max SPL, but less low bass (and if it's WAY too small it just sounds constrained and bad)...

[Still learning]

i made a rough drawing of the box here
<img src=http://tinypic.com/fa7znb.jpg></img src>

[Still learning]

i made a rough drawing of the box here
<img src="http://tinypic.com/fa7znb.jpg">

[Still learning]

i made a rough drawing of the box here
<img src="http://tinypic.com/fa7znb.jpg"></imgsrc>

[Still learning]

i made a rough drawing of the box here
<imgsrc="http://tinypic.com/fa7znb.jpg"></img>

[Still learning]

why in the hell did that happen??? my bad....

[Still learning]

Ok well heres just the link...

http://tinypic.com/fa7znb.jpg

I havent decided if i want to make it to stand like that, or sub on top of eachother.(vertical)

[neomagus00]

fyi, it's "slash img" without the "src" at the end...

and could you fit them vertically? cause i rather like the box you have drawn...

[Dennis Gardner]

Your boxes aren't big...........I use 2-5 cubic foot EBS Adire alignment 12" Shivas in a single box. I don't know what it weighs, since I can't lift it , but it doesn't move around alot when bumpin'.

Edit:.............Sorry guys this is my HT sub. I didn't see this was in the CA forum when responding. In my car I use 2 boxes also, but they are .7 cu. ft. sealed with 10" ID4s.

[neomagus00]

I didn't see this was in the CA forum when responding.

it's okay, we'll forgive your trespass... this time... :D

[Dennis Gardner]

With all threads having the same background with this version of vbulletin, I get lost on occasion. No more black backgound to warn me of my wander. :D

[Still learning]

fyi, it's "slash img" without the "src" at the end...

and could you fit them vertically? cause i rather like the box you have drawn...

damn, thats what my problem was!!!! i was trying to figure it out and i was pushing the "back" button then editing it again and again, all out of the blues, BAM!! all of them showed up, oh well, those internet design classes didnt really stick.

[Still learning]

Your boxes aren't big...........I use 2-5 cubic foot EBS Adire alignment 12" Shivas in a single box. I don't know what it weighs, since I can't lift it , but it doesn't move around alot when bumpin'.

Edit:.............Sorry guys this is my HT sub. I didn't see this was in the CA forum when responding. In my car I use 2 boxes also, but they are .7 cu. ft. sealed with 10" ID4s.

Well the manufactures reccomended, 1.3 cubic feet per sub, so thats what i was going by.

[Still learning]

I think im making this way more complicated than it is......????

and i havent even came to the right solution, any ideas how to make a trapazoidal box exactly 1.3 cubic feet?

[Still learning]

Oh by the way i know you guys are going to hate me for this but, here are the subs that im bulding the box for,

Right Here

What can i say, i saw some guy who had them in the 1.3 cubic foot box, and they sounded great, i have no clue why, but i get sony subs for just about free, because of a guy i know and his store went to ****, so i get the subs for cheap. Its an experement, plus ill probibly end up selling them in the end. I havent herd any systems that can beat mine(with the same stats of course)

[MacLeod]

Your boxes aren't big...........I use 2-5 cubic foot EBS Adire alignment 12" Shivas in a single box. I don't know what it weighs, since I can't lift it , but it doesn't move around alot when bumpin'.

Edit:.............Sorry guys this is my HT sub. I didn't see this was in the CA forum when responding. In my car I use 2 boxes also, but they are .7 cu. ft. sealed with 10" ID4s.

LOL!! I was about to say, 2-5 cubic feet!!! My gawd!!


If the manufacturer recommends 1.3 ft3 thats what you should go with. After all, theyre the ones that designed it and will know what works best with it.

Here are some links to great box construction tutorials. Its basic stuff but lots of good info nonetheless.

MTX website

JL Audio website

[neomagus00]

not quite complicated enough, you were missing the width of the box :p... and yes, i can come up with a box design, but i need to know how steep you want the front face... the attached box gives you a volume damn near 1.3, all you do is build a pair, having them share one wall... and it allows you to mount a 12" sub, unlike the ones you were designing :D

p.s. measurements are in inches... and the pic is roughly to scale, but the face is at roughly 35 degrees from vertical in real life...

[hellohello]

We dont hate you for buying sony, what works for you works for you. Just probably wouldnt work for some of the people here :P

[Still learning]

not quite complicated enough, you were missing the width of the box :p... and yes, i can come up with a box design, but i need to know how steep you want the front face... the attached box gives you a volume damn near 1.3, all you do is build a pair, having them share one wall... and it allows you to mount a 12" sub, unlike the ones you were designing :D

p.s. measurements are in inches... and the pic is roughly to scale, but the face is at roughly 35 degrees from vertical in real life...

What program did you use to make that design?

[Still learning]

I think i figured it out, box, buy splitting the box in half it make two trapidoidal boxs, thus the FORMULA for finding the surface area of a trapazoid is A=(b1+b2)/2


So i found that there is 2246.4 inches Cubed in 1.3 cubic feet,(i converted that because the measurements im using in inches) the hight has to be at least 14 inches so i started with that, i divided 2246.4 inches cubed by 14 to get the needed surface area of the base.

I played around with different dementions untill i got the box to 2245.95 inches cubed, not that is extremely close to 1.3 cubic ft (2246.4 in cubed) ill post the data later just so we can double check.

Thanks

[hellohello]

the12volt.com has box calculators

[neomagus00]

What program did you use to make that design?

my hand and a couple scribbles on a piece of paper :p

also note that, since you're doing internal dimensions, your minimum is about 12.5" for the mounting face of the sub, not necessarily 14"...

[Still learning]

Yea,but the outside edges of the sub are 13.85 inch wibe so you know

P.S, your trying to tell me that drawing is drawn with paper?

[neomagus00]

no, i drew a scribble and then used Paint to draw that image... do you really think a physics guy has handwriting like that?!

and yes, i suppose that 14" couldn't hurt, but you don't NEED more than 12.5"...

[Still learning]

Here are the plans, what do you guy think?

http://tinypic.com/fbjn00.jpg

Im only about 10 pices of paper short.

Oh and you meant to say that, i could mount the sub with the edge over the sides and the mounting holes right at the edge? This is alredy the smallest 2 12s box i have ever seen.

P.S. A couple of random questions, With the sealed and ported box thing, how mush of a "bass" level difference, because you know, you get more pound when it ported? And why is the box so small? I would have thought that the box would be way bigger, i mean the subs are a half of an inch from toutching eachother and a half and inch maby even 1/8 of an inch form the edge, this box is tiny. One more, if i had a 10" sub that could withstand 300 watts RMS, and a 12" 500 watts RMS, would the 12 pound harder if i had the same(200 watt RMS) amp hooked up to bolth of them?

[neomagus00]

for a given wattage, a 12 should hit deeper, and probably louder too (check the sensitivities)... and the canonical figure for ported is +3dB over sealed... and as long as the box is the right volume, that's all that matters... is that the final design?