Volume Calculator and Box Builder

[theFBI]

Hello and Welcome to my post!

Has anyone ever gone to get help for a sub enclosure, and had NO luck?

I took time outta my busy life and created the Volume Calculator and Sub Box builder!

It's not the best piece of machinery, yet. However I'm still working on it!

I need people to test this program and see if they like it, what to change, errors, etc...

The Program is free, so testers aren't being paid either! Sorry, thems tha brakes.

When the program is looking better, I'll post a more professional ad...

Check it out at:
http://www.12voltice.com/volume.zip

Please e-mail comments, or post them here: spyder_crazy[AT]hotmail.com

[djman37]

i'm not loading a zipped file to my computer. someone ELSE check it out first.

[hofulstrof]

work great for those after sealed boxes or possalb tppl using round ports

[PSturmer]

i'm not loading a zipped file to my computer. someone ELSE check it out first.

yeah same dude i aint going to open that. i am not that stupid

[POLKAT]

AVG Free says its clean!

Nice, simple little program.

[Trixter]

well, nice and simple....but what about ports...or am i missing something? did'nt find anything for tuning or port size. also why only 1 or 2 subs?...just some suggestions.... i do like the cut sheet it provides. i think it would be easier to read the cut sheet if was displayed like....

top/bottom: XX" x XX"
front/back" XX" x XX"
sides: XX" x XX"

and had a print option.....also if it actually showed how the pieces go together (which edges go where) so you don't end up with it missized (you know what i mean) and have the drawing and sizes on the same printable page.

i put in dimensions for a box that is 16 x 30 x 15 and it say i need 2 tops (32.25" x 17.25"), a face and a back (32.25" x 16"), and 3 sides (15" x 16")....3 sides?

not to pick it all apart, i do like the idea of it....but could still use a lot of work.

[theFBI]

Great Points Trixter!
Most of the Code is actually in the box in the volume Calculator lol, making the box move.

I'm not entirely in the mood to do that for the Box Builder, however, I totally understand your point! So I will draw the pieces you need, but they won't be ratioed(sp?) to the specific, specs.

And no quetion about add, the how to create it, great idea, still in the works, and was previously planned.

I don't know the formula's for the other stuff, if someone would like to help, don't be shy... lol

-Brian

p.S. Thanks for trusting me, and opening the program. It's appreciated.


Trixter: The Third side is in the middle. So each Sub has it's own Chamber... I will specify that.

[Trixter]

thats where the 3rd "side" is...ok

well maybe this will help:

Lv = (1.463 x 10^7 x R^2) / (Fb^2 x Vb) - 1.463 R

Lv = port length
Fb = tuning freq.
Vb = box volume (cu")
R = radius of port (if using slot or square port then R = sq.rt of A/Pi)

you'll need to do the math, internal w/ sub displacement, to get the length of the the port. once you know the length, you'll need to find it's displacement (including materials of construction) and do the math again...subtracting the port displacement from the Vb...to get you actual number. (really you can keep going back and forth but the difference is so small it don't matter, once is enough.)

also, if the port shares a common wall with the box (most slot ports) you need to account for the port correction factor. this is done by adding 1/2 of the port's width to it's length.

i can help you with the numbers and formulas, but i don't know squat about programming.

if you can do all this....you the man.

need anythign else, lmk.

have fun.

[Alpine4x4]

Hows this coming along?

[theFBI]

Getting busy at work... I tried to add Trixter to msn for help, but haven't seen him online.

Feel free to help:
spyder_crazy [AT] hotmail.com <-- me

You don't need to know much about programing, just math...

[Trixter]

i am rarely on msn...my phone is always on aim though, and with me. and i can't do aim, msn, yahoo or stuff on my work computer due to security reasons. i am at home after 4pm central.

[theFBI]

This is My Subwoofer... ( and actually the brand that I sell )

VW12.2D Specifications
Power RMS : 1600W
Peak Power : 2400W
FS : 25.61Hz
Qts : 0.39
VAS (litres) : 38.17
Xmax : 16mm
Sensitivity : 83.2dB
Magnet Wt. : 200oz
Mtg. Depth : 7.125"
Mtg. Hole Dia. : 11.25"
Displacement : 0.17cu. ft.
Net Weight : 44lbs

These are it's recommendations:
Recommended Enclosure Sizes
Sealed (cu. ft.) : 1.30
Vented (cu. ft.) : 2.50

How do I figure out the port/porting... In Both Round and Square...
I learn best from someone else showing, then I can make it into code.

-Brian

p.S.
The subwoofer is the voodoo 12" Warrior series subwoofer Check it out : 375 $us shipped.

[Trixter]

ok...lets say your going to use the 2.50cu' box and port it with a slot port that has 40sq" and tune it to 30Hz...


Lv = [(1.463 x 10^7 x R^2) / (Fb^2 x Vb)] - 1.463R

to find the value of R on a slot port: sq. rt. of area/Pi so...sq.rt or 40 / 3.14 = 3.57
remember Vb is in cu" so we will multiply 2.50 by 1728 to get 4320
Fb is Hz^2 so this is 900

Lv = [(14630000 x 12.74) / (900 x 4320)] - 1.463 x 3.57
Lv = (186386200 / 3888000) - 5.22
Lv = 47.94 - 5.22
Lv = 42.72

so lets's do the same thing only using 4" round port. we'll use 3 that will give us 37.68sq"....close enough to 40sq".

first we need to divide the Vb by the number of ports so the is 4320 / 3 = 1440. use this for the Vb.

so...

(R is actually the radius this time)

Lv = (14630000 x 4) / (900 x 1440) - 1.463 x 2
Lv = (58520000 / 1296000) - 2.926
Lv = 45.15 - 2.926
Lv = 42.23 for each port

either way we do it, now that we have the port lengths, we need to account for the port displacement.

for the slot port, since we're assuming that it shares a common will with the box, we need to account for the internal volume and teh material it's made up of. let's say we used 3/4" mdf. we already accounted for the top, one side and the front of the port because this is the same as the box.

44.36 - .75 ( for the front of the box) = 43.61----long
12.5 tall (internal)
3.25 + .75 (inner port wall) 4
44.36 x 12.5 x 4 = 2218

subtract 2218 from you original Vb and re do the math to get you new port length.

so if you have a 12" sub and the box is 14" tall (12.5" internal) and if this port shares a common wall with the box then we need to add 1/2 of the port's width to this length. ( since we're 12.5" tall to get 40sq" we need to be about 3.25" wide, so we'll add 1.625" to the Lv we got above.)
THIS IS ONLY IF THE PORT AND BOX SHARE A WALL!

the same is true with round ports. Pi x R^2 x length x number of ports. subtract this number from your original Vb and redo the math. if your ports mount from the outside of the box, you will need to account for the front of the box like you did with the slot port.

hope this helps.

[theFBI]

ya kinda lose me at the end...

Let's just work with a Round port for the time being.
Where does: 40sq" come from.

I have my newly designed box like this:

4" port at 5.86" long, tuned for 38hertz. (It's an SPL sub)
Encluse size is: 2.67cu ft. (2.5 plus Sub Displacement, 0.17)
Round Port, only one.

Funny story, I had one designed for a 17hertz box, then realized the human ear can only hear down to 20hertz lol. 46" or something like that lol.