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View Full Version : Figuring out missing dimension/volume?



Jdg784
02-19-2003, 06:49 PM
Alright..here's the box I have in mind for my Brahma 15", I designed it base on the space I have leftover from removing part of the backseat in my extended cab F-150. Just realized that I don't have a dimension for the faceplace, anyone have a good method of figuring the length out w/out actually building it? Also..anyone have the idea of the volume of this box? Sorry if I made any mistakes, I feel like **** right now and am on more medicine than I can keep track of. Thanks Jeremy~

Trixter
02-19-2003, 10:26 PM
I always devide the enclosure into as many cubes as I can. from what I see of yours you have 3...

one being the base- 2"tall x 19" long x 19" deep (2 x 19 x19 / 1728 = 0.42)
one being the back- 2"deep x 20" high x 19" deep (2 x 20 x 19 / 1728 = 0.44)
one being the rest- 17"deep x 18" tall x 19" wide
(since this one is really a triangle we'll cut it in half- 17 x 18 x 19 / 1728 = 3.36 / 2 = 1.68)

so now we have 0.42 + 0.44 + 1.68 = 3.68

...Make sence?

paikiah
02-19-2003, 10:28 PM
Originally posted by Jdg784
Alright..here's the box I have in mind for my Brahma 15", I designed it base on the space I have leftover from removing part of the backseat in my extended cab F-150. Just realized that I don't have a dimension for the faceplace, anyone have a good method of figuring the length out w/out actually building it? Also..anyone have the idea of the volume of this box? Sorry if I made any mistakes, I feel like **** right now and am on more medicine than I can keep track of. Thanks Jeremy~

looks like someone's missed out on a lot of math classes..;)

Trixter
02-19-2003, 10:34 PM
Oh yah, the missing length you are looking for should be 24.76"
(17x17=289) + (18x18=324) = 613 sq. rt. of 613=24.76

Jdg784
02-19-2003, 11:16 PM
Lol, not a lot of math classes, just a lot of sleep..that mixed w/strong medication. Bronchitis from hell. ..and look at me, still posting away on here..**** car audio addiction, thanks for the help guys.

Jdg784
02-20-2003, 10:38 PM
Thanks for the effort trixter..but your volume calculations are off, you accounted for the same area more than once.

Jdg784
02-20-2003, 10:44 PM
n/m, you just added wrong at the end..my bad

mgaidica
02-20-2003, 11:41 PM
when doing box stuff i just set out like a sheet of wrapping paper, and it helps a lot to plan things... just a though...

Jdg784
02-21-2003, 12:37 AM
good call, never thought about doing that really, I've drawn up plans..but never full size

Trixter
02-21-2003, 11:33 AM
Figures, the hard stuff is easy and the easy stuff is hard...isn't that the way it always goes though?

Is 2.5cu' your target vol.? What is recommended?

Jdg784
02-21-2003, 05:22 PM
I didn't have a particular targer volume, but it came out rather well. At 2.54 ft^3 I can run the JBL 1200.1 at 4ohms to break it in..and 2 ohms afterwards. The brahma can easily handle 1200 watts in that box.
Box Size (ft3)
Power
2.85ft ^3
800W

1.89ft ^3
1200W

1.34ft ^3
1800W

1.01ft ^3
2500W

Trixter
02-21-2003, 07:19 PM
Sounds good.:)