Boxes

Mycophiles

Registered
I am making a box for the back of my Mark. I have not measured the trunk so I dont know the dimensions the box can be. Ill do that tomarrow. Anyone have this offhand?

I have a single Brahma 12" that I am putting in the car. I want the box ported but I have no idea how to make a ported box. I hear its not as easy as building the box and putting a hole in it but I dont know. I figure the way to build it would be like this.




http://users3.ev1.net/~acashiola/front.bmp


And the inside will be like this.


http://users3.ev1.net/~acashiola/inside.bmp


I'm not sure about the demensions of the box yet. I also need a suggestion on the size of the box. How much room should I have in there. (not huge) I have about half the back of my trunk I want to use and I am going to be running it off a crossfire 1000d.


OHHH and what kind of Wood do I/ Can I use?
 

MaddShadez

Registered
RE: Boxes

You should use at least 3/4 inch MDF, or medium density fiberboard. You can also use HDF, or high density, it is stronger, but heavier as well. Most boxes already weigh 30-50 pounds. Don not use thinner than 3/4 inch.


Building a ported box is literally a science. Many factors have to be taken into account when building one, such as box size, port size, and the area or the port. It's not as simple as putting a hole in a box.

When a sub makes music, it not only pushes sound waves out in front, but also behind it. In a ported box, you are capturing those sound waves, and combining them with the forward sound waves (at a specific angle so they don't cancel each other out) and therefore making twice as much volume. If you don't have all the calculations right, it will sound like crap. When you tune your port, you are tuning to a specific frequency. Any music below that frequency can destroy your sub. YOU MUST USE A SUBSONIC FILTER WITH PORTED BOXES! I cannot stress that enough. Below the tuning frequency, the motor losses the ability to control the cone. and poof, your sub is toast.

You can email The guys at Adire for exact specs if you want to try. Despite what you may hear (cough Paul, cough man I havea cold too :)), sealed is not a bad way to go at all.


BTW it's been a while but i beleive your working space is around 37" across, about 13 inches on the bottom from the spare tire cover back, and 7 inches on top back. Oh yeah and roughly 15 inches of height. That would give you enough room to remove your tire cover, assuming you no longer have the black plastic thing in ur trunk. And it gives you about 3.2 cubes to work with, not counting displacment of the wood or woofer. But double check my measurements.
 

Mycophiles

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RE: Boxes

What kind of frequency do I want to tune this thing too? Im lost here. Should I tune it's lowest frequency which is I think 23htz or should I look to something higher?

Am I totally off the mark here?

The sub will be accompanied by the focal 165v's that are in the doors now if that makes any diff. in your opinion.
 

MaddShadez

Registered
RE: Boxes

The frequency yo utune it to is largly dependent on the sub. Every woofer has a certain peak frequency that will get you that extra bit of volume. I honestly do not know what it is for the brahma. I've never built a ported box, so I haven't kept up with the specs like I should. If you email Dan wiggins from Adire, he is a really cool guy, who loves to help people. He can fill you in more on exact tuning frequencies for the brahma.
 

Mycophiles

Registered
RE: Boxes

I think I'm going to tune it to 25 hz. Im still researching it though. I emailed Dan wiggins about those box deminsions so I should be able to start the building soon. Im a patient person but I am getting ancy. If I can get the RAAAmat this weekand I would have it in by monday therefore half the work would be done. As of now I'm twiddling my thumbs.
 

Mycophiles

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RE: Boxes

I got a problem. The sub is 12" around and in the trunk the measurements from the top (underhang thing) to the bottom is 10 inches. Did ya'll take the top underhang thingy out to put your sub in?

BTW I'm going enclosed for now. I think I'll do a 2.0 cubic foot box. Therefore taking the entire back of the trunk up, but that's ok I dont use any of that anyway.
 

Mycophiles

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RE: Boxes

Well I've just been told that a 1.2 cubed box would work best if its sealed. But I still run into the problem of how to get a 14 inch high box into the trunk.
 

jbuch

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RE: Boxes

I could be mistaken, but if you take that plastic cover off, the factory amp should be right there. Get rid of the amp, leave the plastic piece off, and you should have enough room.

If you're keeping your factory amp, well, someone with more experience will have to help you there.
 

Mycophiles

Registered
RE: Boxes

The factory amp is gone and its been replaced but the black plastic cover thing has now found its new home in the garage. There a black piece of metal/plastic the factory amp sits on and that's what I'm talking about.
 

MaddShadez

Registered
RE: Boxes

I thought real hard about making an angled box, but in the end didn't have the right tools to do it. I madea regular rectangle and it fits fine, I forget how deep I made it though. I think it's like 10 inches, I'll check sometime.
 

M Darrah

Registered
RE: Boxes

Does anyone know if the height clearance is the same as the T-Bird? I was hoping to use the box from my wrecked 95 'bird in the Mark. It's got two 10" Boston subs in it, with the amps on top. I had two or three inches of clearance before.
 

johnaec

Registered
RE: Boxes

The T-Bird has much more clearance. I have a box I use for tools that fits under the T-Bird deck with plenty of room, bot won't even come close if I try putting it in the Mark VIII.

John
'97 Mark VIII LSC
'96 T-Bird 4.6 LX
 
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