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View Full Version : is it better to make a box with or without sub displacement?



waggs
12-25-2006, 12:55 AM
i wanna make a box for a fi q 12. i designed one with and another without sub displacement using re's box calculator. before disp. it was 2.3 @33hz. is it o.k. to use the plan without displacement or do i have to include that in the design? thanks in advance

phyphoestilic
12-25-2006, 01:08 AM
u can use the plan before displacement, but its better to use the one after displacement because that .16 cft3 from the sub will change the tunning a little. Unless ur mounting the sub inverted.

ultimate157
12-25-2006, 01:09 AM
include it to get the correct volume and tuning

ngsm13
12-25-2006, 01:15 AM
Ok, what's the REAL question.

Make? or Design?

That is the real question.

nG

waggs
12-25-2006, 01:23 AM
Ok, what's the REAL question.

Make? or Design?

That is the real question.

nG
design, then make:)

ngsm13
12-25-2006, 01:41 AM
There's so many calculators and bullshit online I honestly don't know what to tell you.

Personally, I used winISD Pro most of the time if I have a computer nearby, if not it's by hand with a calculator.

MOST calculators just spit out a port length.

All the calculator cares about is NET volume. The volume with subwoofer atually "sees" after all displacements.

So, given a NET volume, a port area, and a tuning, it spits out a port length.

THEN, you must take you NET volume... add to that the port displacement volume... and the speaker displacement volume. Then you get the final GROSS internal volume the enclosure needs to be.

This is the only way to really correctly design a proper enclosure.

nG

iamamp3pimp
12-25-2006, 07:36 AM
thats how i do it.

evan
12-25-2006, 01:50 PM
Don't forget to include the displacement of any bracing you use.

waggs
12-25-2006, 07:34 PM
can someone help me with the design of my 12" fi-q box? the biggest box i can fit in my car is 21Wx21Dx14.5H. i want it at 2.2@33hz after displacment. is this even possible? i feel like i've tried every design but nothing works. thanks in advance.

ngsm13
12-25-2006, 07:39 PM
can someone help me with the design of my 12" fi-q box? the biggest box i can fit in my car is 21Wx21Dx14.5H. i want it at 2.2@33hz after displacment. is this even possible? i feel like i've tried every design but nothing works. thanks in advance.

It'll be hard.

I'd shoot for 2cubes @33hz, with my 20-30 sq. in. of port

nG

waggs
12-25-2006, 07:43 PM
It'll be hard.

I'd shoot for 2cubes @33hz, with my 20-30 sq. in. of port

nG
will the q still sound good with that amount of space? i'm looking for great sq but also something loud...

ngsm13
12-25-2006, 07:44 PM
Yup, it will.

nG

rpfuror
12-25-2006, 07:49 PM
Here you go, fits your spec perfectly:

Desired Tuning Freq: 32.00 Hz
Slot Vent Width: 2.00 inches
Wood Thickness: 0.75 inches
Driver Displacment: 0.18 cu/ft
Number of Drivers: 1.00 qty
Width= 21.00 inches
Height= 15.00 inches
Depth= 21.00 inches
Port Length= 28.01 inches
Driver Volume= 2.19 cu/ft
Port Area= 27.00 sq/in

PM me I can give you box cutts and/or a 3d drawing

waggs
12-25-2006, 07:55 PM
Here you go, fits yout spec perfectly:

Desired Tuning Freq: 32.00 Hz
Slot Vent Width: 2.00 inches
Wood Thickness: 0.75 inches
Driver Displacment: 0.18 cu/ft
Number of Drivers: 1.00 qty
Width= 21.00 inches
Height= 15.00 inches
Depth= 21.00 inches
Port Length= 28.01 inches
Driver Volume= 2.19 cu/ft
Port Area= 27.00 sq/in

PM me I can give you box cutts and/or a 3d drawing
ooo so close:crap: i'm gonna fold the back seats down and slide the box in from the inside. the hight of the opening is 14 5/8" and i'm gonna try to squeeze 14 1/2 in through there. thanks for trying:)

rpfuror
12-25-2006, 07:58 PM
I just worked with your dimentions,

you can get 2.1 cu/ft @ 34 Hz with the following:

Slot Vent Width: 2.00 inches
Wood Thickness: 0.75 inches
Driver Displacment: 0.18 cu/ft
Number of Drivers: 1.00 qty
Width= 21.00 inches
Height= 14.00 inches
Depth= 21.00 inches
Port Length= 23.63 inches
Driver Volume= 2.10 cu/ft
Port Area= 25.00 sq/in

waggs
12-25-2006, 08:05 PM
I just worked with your dimentions,

you can get 2.1 cu/ft @ 34 Hz with the following:

Slot Vent Width: 2.00 inches
Wood Thickness: 0.75 inches
Driver Displacment: 0.18 cu/ft
Number of Drivers: 1.00 qty
Width= 21.00 inches
Height= 14.00 inches
Depth= 21.00 inches
Port Length= 23.63 inches
Driver Volume= 2.10 cu/ft
Port Area= 25.00 sq/in
ygpm

rpfuror
12-25-2006, 08:33 PM
Per your request, here is a 3d drawing:

http://i135.photobucket.com/albums/q145/rpfuror/2-2.jpg

waggs
12-25-2006, 08:51 PM
Per your request, here is a 3d drawing:

http://i135.photobucket.com/albums/q145/rpfuror/2-2.jpg
thanks:) looks good. btw, how long are the 2 port pieces?

rpfuror
12-25-2006, 09:33 PM
17.50" x 12.50" first
2.0" x 12.5" second