Volume of a box is 1 ft^3.....

[Cuda1447]

That means the box is 1 by 1 by 1.


Im building a subwoofer box (Well trying to atleast) and the sealed box volume provided by infinity is 1 ft cubed. So am I really supposed to make a 1 by 1 by 1 box for this sub?!? It seems kinda small to me.


Im probably missing something, any help would be greatly appreciated.

 

[booger711]

it could be 2 x 1 x 0.5
get the actual dimensions of the sub before you build
what the hell do they say? ...
measure twice cut once?

 

[ActuaryTm]

"Infinite Diversity in Infinite Combinations."

(hint: dimensions of the box can be any size, and produce a volume of one cubic foot)

 

[Viper GTS]

You need to account for the displacement of internal components (primarily the cone + motor/frame of the sub, plus ports/bracing/etc.). Infinity should be able to provide you with a correction value to use, unless they already accounted for that.

Viper GTS

 

[Cuda1447]

Kappa Perfect 12.1 Sub. Im trying to find the dimensions of the sub, no luck yet.

 

[dethman]

maket he box 1 x one bajillion feet x .0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001 ft.

 

[Beau]

Do a search for the Blaupunkt Subwoofer enclosure program. Very cool design program.

 

[Viper GTS]

Originally posted by: Cuda1447
Kappa Perfect 12.1 Sub. Im trying to find the dimensions of the sub, no luck yet.

Worst case, put it in a loose fitting plastic bag & dip it in water up to the level that will be inside the box. Not precise, but it will work.

Viper GTS

 

[Cuda1447]

Originally posted by: Beau
Do a search for the Blaupunkt Subwoofer enclosure program. Very cool design program.

Search on google didn't bring up anything

 

[Beau]

Originally posted by: Cuda1447

Originally posted by: Beau
Do a search for the Blaupunkt Subwoofer enclosure program. Very cool design program.

Search on google didn't bring up anything

It's pretty old. I wonder if I'd get in trouble for redistributing it.

 

[Cuda1447]

Alright the mounting depth is 6 and 1/4 inches. The cut-out diamter is 10 and 15/16 inches.

 

[Beau]

ygpm

 

[brian_riendeau]

1 cube or slightly larger is quite common for a single 12. Once you build the box in a cube shape, it actually looks fairly big I built a 1.25 cube box a couple days ago, I just did a box shape for simplicity.

Also do not forget to subtract the displacement of the sub from the total volume of the box.

Check out my previous handiwork here, you should be able to find a bunch of techniques to help you out on your first box:

http://www.sounddomain.com/id/brian_r

Let me know if you have any questions, I have built a bunch of these...

 

[Cuda1447]

Ok, I guess Ive got the dimensions of the box about figured out. But I need to add bracing for the box (which I didn't realize before). The problem is I don't really understand how the bracing is supposed to be constructed.

 

[BigPoppa]

Please take into account the thickness of the MDF you're building the box with also. The volume displacement of a typical sub is 0.1-0.2 cu. ft.

Using 3/4" MDF:

Cut 4 pieces 13.25 wide x 12.5 tall - these form the 4 sides. "Stagger" the wall joints. Hard to explain. One walls "face" will go to another walls "end". (Face + end = 13.25 + 0.75 = 14" wall)
Cut 2 pieces 14x14 - top.

Use self tapping sheet rock screws, this way you won't have to pre-drill. Use wood glue on all wood to wood joints (basically every edge ). Once the box dries, lightly caulk the seams to ensure an airtight chamber. To run speaker wire, I usually drill a hole just big enough to fit the wire through, then either fill the hole with caulk or epoxy. Make sure to leave some excess wire in the box for future tweaking you may or may not do.

Gives an internal box dimension of 12.5x12.5x12.5 = 1.13 cu ft internal volume before driver displacement. With average driver displacement, you'll be fine either way.

 

[Viper GTS]

Originally posted by: Cuda1447
Ok, I guess Ive got the dimensions of the box about figured out. But I need to add bracing for the box (which I didn't realize before). The problem is I don't really understand how the bracing is supposed to be constructed.

Look here for examples:

http://www.adireaudio.com/File...empestApplications.PDF

Obviously none of the dimensions will be the same, but it should give you an idea.

Also, you need the physical DISPLACEMENT of the driver (not the linear displacement that tells how much the cone can move). The dimensions you have posted are not what you need.

BigPoppa's "average value" may be fine, it doesn't have to be terribly precise.

Viper GTS

 

[GRIFFIN1]

Is this going in a car? If it is, then where you plan on mounting the speaker will determine the shape of the box.

I don't think I would worry too much about determining the volume that the driver will take up. Since Infinity didn't give you the volume of the driver, then I would assume that they have already figured that volume into the final volume of the box. One cubic foot is small, but car speakers are made to go in small boxes.

 

[brian_riendeau]

Use self tapping sheet rock screws, this way you won't have to pre-drill.

Nooo... With MDF, you really should predrill the wholes and countersink the screws if you really want a solid box. Many, many people have split the edges of MDFs by not predrilling. Makes for a really ugly box if this happens, all to save a few minutes of predrilling.

But I need to add bracing for the box (which I didn't realize before).

You do not need bracing in a 1 ft^3 box if you build it right and run less than 2000w or so to the sub.

 

[BigPoppa]

Originally posted by: Cuda1447
Ok, I guess Ive got the dimensions of the box about figured out. But I need to add bracing for the box (which I didn't realize before). The problem is I don't really understand how the bracing is supposed to be constructed.

Bracing can be done quite a few ways. You could cut some 90 degree triangles of MDF and brace areas where 2 panels meet together. This will help stop the flexing of the MDF, although it depends on how much power you're running to the 12.1. If you're pushing 500-700 (wouldn't go over this with a 12.1) there will most likely be some flexing if you don't brace. Also take the displacement of the bracing into account in your final box volume too.

Another form of bracing I've heard of is cutting out equilateral triangles and using them in the corner of the box. These will also help the reflection of the backwaves.

 

[MikeMike]

eh, a 1 cube box doesnt really need that much bracing, plus you wont see much of a difference unless your pushing a lot of power. The key with mdf is that almost guarenteed it will split on you, predrilling the holes will help a small amount, but the screws are really there just to hold it together until the glue dries. then the glue is what holds it together.

MIKE

 

[Cuda1447]

Originally posted by: brian_riendeau

Use self tapping sheet rock screws, this way you won't have to pre-drill.

Nooo... With MDF, you really should predrill the wholes and countersink the screws if you really want a solid box. Many, many people have split the edges of MDFs by not predrilling. Makes for a really ugly box if this happens, all to save a few minutes of predrilling.

But I need to add bracing for the box (which I didn't realize before).

You do not need bracing in a 1 ft^3 box if you build it right and run less than 2000w or so to the sub.

So basically I don't really need to worry to much about bracing it? I'd be ok if I just built a basic square box to the proper dimensions since the displacement has already been factored in by Infinity most likely?

 

[glen]

The TS parameters for each driver are going to vary more than the amount of the driver's internal dispalcement. You don't have to be that exact.

 

[brian_riendeau]

So basically I don't really need to worry to much about bracing it? I'd be ok if I just built a basic square box to the proper dimensions since the displacement has already been factored in by Infinity most likely?

Build the box properly and it will not need bracing. If it falls apart with a 12.1, you did something wrong and it would have broken regardless of how much you braced it Since this is your first box, just make a box shape, then you can mess around later. You can get enough MDF to build 2 or 3 sealed boxes at Home Depot for $20.

Sub manufacturers do not take into account the volume of the sub when giving a volume reccomendation. When they say 1 ft^3 reccomended box size, and the sub displaces .1ft^3, the acutally internal volume of the box needs to be 1.1ft^3. Then take out the displacement of the sub, and the speaker would have the correct the 1ft^3 air volume to work with.