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View Full Version : Need a bit of help...I **** at math

Lonnie
09-09-2009, 06:43 PM
Well stuff to do with Geometry and measurement. Which is why im forced to take a Basic Algebra+Measurement class right now lmao. Havent really covered enough for me to accurately calculate or even understand some of the terms. Whats really throwing me off is wtf is depth? And how exactly does tuning a ported box work?

Wanting to put 2 12" Type Rs in my trunk in a ported box. Was told a Prefab ***** so yea. Just took a few measurements of my trunk space...went to the RE enclosure calculator and its asking for depth...wtf?

Measurements are 42" X 14" X 22"

Knew I should have payed attention in geometry in high school lmao. Then maybe I wouldnt be going wtf? Also would be taking Auto Body right now instead of a **** measurement class.

09-09-2009, 06:48 PM
25?

TurdFergueson2
09-09-2009, 06:53 PM
You got like little over 9 cubic feet to work with.

Lonnie
09-09-2009, 06:55 PM
O WAIT

Just figured out what depth was I think. Isnt it the distance from the back of the trunk to the front? Well not going to fill the entire trunk up but if thats it then its 22". Also just figured out the port size determines the frequency. Wow just answered my own questions...

JimJ
09-09-2009, 06:57 PM
Three dimensions...length, width, depth...

TurdFergueson2
09-09-2009, 06:59 PM
7.5 cubes then

Lonnie
09-09-2009, 07:10 PM
Ok so if I make a box to the exact dimensions that can fit in my trunk it would be 7.5 cubic inches?

Specs says this:

Ported Box Volume (cubic feet) 0.75 - 2

http://www.crutchfield.com/p_500SWR1242/Alpine-SWR-1242D.html?tp=111&tab=features_and_specs

So then each sub area would take up .75"^3 to 2"^3 of space which would leave 2"^3 of space left. Is that too much? Well the port area would take up some...really just plan on doing it simple it keeping the same design as a prefab lol. With the port area in between the 2 subs. Or is that a bad idea?

Also with the tuning...site says it has to be no lower than this:

Fs (Hz) 29

I think I read that 36Hz is better for the type of music I listen to...which is metal/rock. I do listen to a little rap but its really just Fort Minor. Their are some metal bands that have deep hitting base though which is why I decided on a ported box over a sealed. But yea is 36Hz right? How high above 29 can it be? A lot of questions but HEY ive always been told you wont learn a **** thing unless you know how to ask questions.