is there a way...

[mbaoo]

to find out how many cubes and what frequency the ports are tuned to on a box/sub combo I just bought?

Im asking because I got a box with two ported IDQs of craigslist and Im curious as to how many cubes it is and what frequecy the ports are tuned at as the guy who I bought it from doesnt know.

Any ideas?

Click to read more...

 

[grimreper912003 5,000+ posts]

we need volume of the box, How many aero's and what diameter they are, and port lenght

 

[mbaoo]

Hmmmm. Well, the box is slanted at the back. I dont know how I would find the volume of a box like that. I kinda fail with geometry.

I guess I should just wait till tomorrow to figure this out. Its dark and cold out right now.

 

[grimreper912003 5,000+ posts]

Measure the bottom depth and top depth.

bottom depth (-.75) - top depth (-.75) = triangle base

Base * Hight = Area

(Area * width) /1728 = Volume 1

Now (Top depth (-.75) * Width (-1.5) * Hight(-1.5) ) /1728 = Volume 2

Volume 1 + Volume 2 = Internal volume

Assuming its .75" MDF.

 

[mbaoo]

I think I understand what your saying. Like, do I calulate the volume of the triangle side and the rectangular side separately. Then add them together to get the final volume?

 

[pr-festiva 10+ year member]

just measure the dimentions of the box and post it and some one will tell you how many cubes it is.Also give the ports dimentions.

 

[ultimate157 5,000+ posts]

Give these outside dimensions:

Width

Height

Top depth

Bottom depth

The side in your picture has height, top depth, and bottom depth.

 

[mbaoo]

Okay guys. Here are the dimensions for the box.

Top depth- 12 inch

Bottom depth- 19 1/4 inch

Height- 14 1/8 inch

Width- 30 inch

Box contains two round ports (i think they are called aero ports?)

Port length- 9 3/4 inch

Port diameter- 3 inch

I did not take into account for the thickness of the mdf (.75 inch)

Is this enough for one of you guys to figure out box volume and what its tuning is?

 

[mbaoo]

Come on guys.

 

[pr-festiva 10+ year member]

2.867 cube total before sub displacement and if there is a devider that would minus a little too,, looks to be tuned around 34 Hz if the port calc.is correct

 

[mbaoo]

Did you actually do the math or did you use some sort of program?

Can you link me to that or another one so I can see what you did. Im curious and want to see for myself.

 

[brian84corvette 10+ year member]

here u go.

http://www.rockfordfosgate.com/rftech/box_wizard.asp

its super eazy.

 

[mbaoo]

SWEEEEET.

Going by that, my box is 2.94 cubes NOT including sub displacement and such.

Do you have a link for measuring box tuning?

 

[pr-festiva 10+ year member]

got to take into acount the air your ports displace2.867 should be close to your volume

 

[grimreper912003 5,000+ posts]

Try http://www.psp-inc.com for the port calculator.