Box HELP

[Dangercdv 4]

I will be building 2 of these boxes sometime in the next week. There are matched to fit my tiny trunk (00 Mustang Vert)

Each is 0.86896 cubic feet, tuned to 32 or 33hz. Each will house a CompVR 10 inch sub, Seeing around 400rms each.

The boxes are from a friend so they will be free. There replacing prefab sealed boxes about .8 cubes

 

I would like to know if theres anything wrong with my design.

 

 

The port is 12.5 inches wide, by half an inch tall. It extends all the way until it is half an inch from the back wall.

[altoncustomtech 773]

Right off the bat I can tell you the port size is not going to work.  There's not enough port area and a 25:1 port ratio is going to cause problems as well.  It will act more like a leaky sealed box than it will a ported enclosure.

 

 

Others may have their own thoughts, but that's what I'm seeing when I look at it.

[Dangercdv 4]

I know the port is going to be a problem but thats really all I can do with what I have.
Will it be better than the sealed prefab box im using now at least? It goes down to like 35hz before I cant hear it anymore

Edited February 19, 2013 by Dangercdv

[Dangercdv 4]

I also thought about adding another piece on top of that. 12.5 wide, and 3 inches tall. It would add to the port area by a little but im not sure it would be worth it? Would this help at all?

[altoncustomtech 773]

A piece on top of what, the back of the port?  That would only add to the port length, not the port area.

 

If that box indeed acted like a leaky sealed enclosure then no, it would not be better than the sealed enclosures you're using now.  The port in a ported enclosure will not function like a port if it is too small and can cause a host of issues when too large.  They generally have to get to the point of ridiculously large to reach that point and more often than not fitting the required length becomes the issue before the too large area does.

 

Do you have any, or tried putting any polyfil in the sealed enclosures you're currently using?  That can help trick or fool (for lack of better words ATM) the subs into thinking they're in larger enclosures.  That could help get you a little on the bottom end with your current setup, although you shouldn't expect miracles either.

[Dangercdv 4]

Im looking for more output from the small space I have. 
Ported is the way everyones telling me to go, and Iv always agreed after hearing other systems, its just the same problem iv always had... SPACE.
This is as big as a box im going to get. Its been measured and it will be free to make. 

Honestly I dotn care if it gets any lower than it does now, I want MORE output. 

 

*I know the ports small, but im looking for a little more. im NOT expecting a large jump in DBs. Just a small noticible difference. And im also trying to get rid of these prefab boxes that dont really fit right in my trunk. iv finally hit the chance to get a free box made. (I could always take out the port and seal it if im not happy)

Edited February 19, 2013 by Dangercdv

[altoncustomtech 773]

Being that they're completely free it wouldn't hurt to try I suppose, but without being able to get more space I just don't see how you can expect to really get any more output from the ported over the sealed.  

 

You're right, everyone's telling you to go that route because in most cases a ported enclosure is louder than a sealed, but that's also assuming the ported enclosure can be built at least close to optimum specifications.  This is a definite case in which optimum is no where near where it's going to end up.

[Dangercdv 4]

I know the box is not near optimal, but il try it out and see how I like it. 
Worse case, I seal it up and I now have a box that fits much better into my trunk thatn the prefabs that cant slide back more than a few inches. 

[altoncustomtech 773]

I think that's definitely a good way to look at it.  Don't discount trying polyfil either.  Providing better low end response is exactly what a ported enclosure does.  It's louder because that's response the sealed cannot provide.  You may be able to make a little of that up with the polyfil if the ported enclosures don't work out.

[Dangercdv 4]

I thought about raising the box so I can make a 12.5 x 1inch port, but it says I need 27.8 inches of port for 35hz tune... would this possible work better?
I could do that...

 

I think I can raise the cubic feet to about 9-9.5, and tune around 35hz with 27 inches of port? This seems more reasonable. 

 

OR, 1 (or 2?) Round ports. 2.5 inch round port, 12 inches long for a 33hz tune? Is this the better option???

Edited February 19, 2013 by Dangercdv

[Dangercdv 4]

What would be better????

12.5x1 inch port, that goes for 27.8 inches (35hz)

OR

1 (maybe 2) round ports 2.5inches, and have them be 12 inches long? (33hz)

 

Id rahter build the sloted box, and I believe it will sound allot better than my original half inch port design

[Dangercdv 4]

Got it now. I raised the front and back height by 1 inch. Raised the port to 1 inch tall now. And 28 inches of port so its 33hz. Much better