Type-R

ok i have heard alot about these boxs and i am wanting to try them out.... i have two apline swr-1221d subs i was thinking about putting them in a abc box... or i have two 12 inch cer-win vega stealths i would also consider putting in one of these boxs.... there is only one problem i dont know how to calculate any of this.... can any one help me please

quadzed

Two 12's? Hope you have a lot of space man.

My two 8" ABC box is about 3 cubic feet in gross volume.

abnormal72

^I have a cerwin vega stealth in a ported box and its around 1 cubic foot.

quadzed

Ported boxes are not ABC boxes, and vice versa.

abnormal72

This is what i came up with for the 2 CV 12"

one side 1.33 cf and the other side

.66 cf

approximately 2cf total

3 ports are 4"d x 5.5"L

I never built one and am going by what i read on this forum

But if you do a search here for ABC box you will find lots of info.

The box is tuned rather high 44hz and a -3db point around 50hz.

abnormal72

Ported boxes are not ABC boxes, and vice versa. </font>[/QUOTE]Isnt an abc box a ported box divided into 2/3 and 1/3? [img]graemlins/dunno.gif[/img]

quadzed

2 cubic feet for two 12's??? Whhoooh that's even way too small for a regular ported box, heck even sealed that's pretty small. I would think between 4 and 6 cubic feet total is what would be needed.

And 44Hz is way too high of a tuning, it will be peaky and boomy, and have no low end. From what I've learned tuning between 28-32Hz is perfect, if mine were a standard ported box it would be 2.93CF tuned to 30Hz. And thats for two EIGHT inch subs.

Type-R email me with your space limitations, I might be able to help you work out a design

[ June 04, 2003, 06:39 PM: Message edited by: hiredgoon ]

abnormal72

mayby the cv 12 is a crappy woofer but tune it to 30 hz in any size box and the response curve goes down the toilet

vas 2.84 cf
fs 32hz
qts .30

also winisd chooses .7 cf sealed

quadzed

Have you heard the Stealths in a low-tuned ported box or did you just assume that because WinISD told you so? Once you put it in a car, you may as well throw the response curve out the window.

Also Type-R has a pair of Alpine Type R 12's if you didn't notice.

abnormal72

Yes i noticed he has 2 alpines, and yes i tryed tuning my cv to a lower frequency

And winisd is not the bible, but all the cabin gain in the world is not going to help you when you tune a box to 30hz and the response starts to roll off at 200hz.

Anyways how do you calculate how a box/woofer setup is going to perform?

I just use winisd to give me a ballpark idea as to how it may work, thats all.

It sure beats running formulas threw a calculator.