is it better to make a box with or without sub displacement?

[waggs 10+ year member]

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

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[phyphoestilic 5,000+ posts]

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 5,000+ posts]

include it to get the correct volume and tuning

 

[ngsm13 5,000+ posts]

Ok, what's the REAL question.

Make? or Design?

That is the real question.

nG

 

[waggs 10+ year member]

Ok, what's the REAL question.
Make? or Design?

That is the real question.

nG

design, then make

 

[ngsm13 5,000+ posts]

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 5,000+ posts]

thats how i do it.

 

[evan 10+ year member]

Don't forget to include the displacement of any bracing you use.

 

[waggs 10+ year member]

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 5,000+ posts]

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 10+ year member]

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 5,000+ posts]

Yup, it will.

nG

 

[rpfuror 10+ year member]

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 10+ year member]

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 10+ year member]

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