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ubrjetgunner

Fi Q12 Enclosure Questions

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whats up! im running a D1 Fi Q12 with a DSC2000.1D @1000watts...but its in a pos pre fab box. I want to step up and build a box with these specs 2.5cf @ 32Hz

how do the dimensions look, will this get me to 32Hz?

Capture-3.jpg

Edited by Slo N Low

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it will be like 33 or 34 after sub displacement but u wont really notice a difference

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That calculator isn't known for being the most accurate.

I got 2.10 Ft3 after all displacements tuned to 31.94 Hz. with 26 in2 port area, you would benefit from more port area.

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I got 2.33ft^3 @ ~34hz after all displacements.

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I got 2.33ft^3 @ ~34hz after all displacements.

i think you forgot to take in to affect the .75 wood thickness of the port instead of a 2 inch opening like the calculator says it would be 2.75 x 13x22 which would make the box 2.27953125 cubic feet with the displacement of port .455 and sub of .16 and the box inside dimensions of 28.5x13.5 x 13 =/1728 = 2.89453125 before displacements. sorry did not calculate the port tune yet .

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I got 2.33ft^3 @ ~34hz after all displacements.

i think you forgot to take in to affect the .75 wood thickness of the port instead of a 2 inch opening like the calculator says it would be 2.75 x 13x22 which would make the box 2.27953125 cubic feet with the displacement of port .455 and sub of .16 and the box inside dimensions of 28.5x13.5 x 13 =/1728 = 2.89453125 before displacements. sorry did not calculate the port tune yet .

When a port bends you can't figure the area the port takes up separately then subtract it from the box volume.

For example the way the calculator I set up figures internal volume is it calulates the volume of the green area then the volume of the orange area depending on the length of the pink board. Then it adds them together and subtracts any displacements you might have.

Example.png

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thanks well i made another box, looks closer to what i was going for

now i gotta get my ass to homedepot and build this beast, you guys have any tips? this will be my first build

bjsfiQ12.png

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take your time, every enclosure i make i fiberglass resin the inside to make it solid, but that's just me

if you have any questions about building it let us know

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I got 2.33ft^3 @ ~34hz after all displacements.

i think you forgot to take in to affect the .75 wood thickness of the port instead of a 2 inch opening like the calculator says it would be 2.75 x 13x22 which would make the box 2.27953125 cubic feet with the displacement of port .455 and sub of .16 and the box inside dimensions of 28.5x13.5 x 13 =/1728 = 2.89453125 before displacements. sorry did not calculate the port tune yet .

When a port bends you can't figure the area the port takes up separately then subtract it from the box volume.

For example the way the calculator I set up figures internal volume is it calulates the volume of the green area then the volume of the orange area depending on the length of the pink board. Then it adds them together and subtracts any displacements you might have.

Example.png

that is one of my points but not in this post you can not calculate displacement before the port is calculated. so why use displacements in the formula? as far as i see it your adding to much air space with those calculators that add in the displacements. so why not just build a box like 2.5 cu-ft and stick a port in it and forget the displacements? all you have to do to make the bass note out of the port falter is make the box bigger yet ? it would be like using displacements.

if you read in to the number that is basically what there doing is calculating and then minus till it fits. which i seen a lot of calculators go way to big on boxes and not play the right note. sounds like a cone fluttering and it was because of the displacements. just like a lot of manufacture will calculate in the displacement in to the ports etc /sub displacements etc... so the box you design become one noteish no mater what. even if you were just to build the box dimensions of a 2.5 calculate the port and stick it in the box. it will play the same as if you add the displacements so you over calculate some what. because of the company calculating more then needed and you add to it. the cone mite flutter like over powering and hitting peak x mech

BTW just trying to figure out why your off of mine by .07 cu-ft mine say there smaller were your says it's bigger yet. could not figure it out but will sooner or later lol's

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that is one of my points but not in this post you can not calculate displacement before the port is calculated. so why use displacements in the formula? as far as i see it your adding to much air space with those calculators that add in the displacements. so why not just build a box like 2.5 cu-ft and stick a port in it and forget the displacements? all you have to do to make the bass note out of the port falter is make the box bigger yet ? it would be like using displacements.

I'm not adding any airspace. The displacements are subtracted from the volume and for reference the displacements I am talking about are like bracing(which there is none in this instance) and sub.

BTW just trying to figure out why your off of mine by .07 cu-ft mine say there smaller were your says it's bigger yet. could not figure it out but will sooner or later lol's

Your off because your calculating to much port displacement.

1. The physical port is only 21" long. So you have an extra .021ft^3

2. You are accounting for 6.25" of port wall that is not there. So then you have an extra .0352ft^3

So your 2.2795ft^3 + (.0352+.021) = 2.33ft^3 that I calculated.

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thanks well i made another box, looks closer to what i was going for

now i gotta get my ass to homedepot and build this beast, you guys have any tips? this will be my first build

bjsfiQ12.png

Glad you found one in the collection, I forgot it was there. If you want one with different dimensions let me know I can whip one up and if you want I could also get creative and do one.

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thanks for the offer man but i bought and cut all the wood today i like to get things done fast haha

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thanks for the offer man but i bought and cut all the wood today i like to get things done fast haha

:orly3: Well lets see some pics then. :)

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2.33 cuft @ 34 Hz is the correct calculation for the first box. The RE calculator SUCKS!!!!!

New box looks better. Only problem I see is the Subsonic filter - Is it fixed at 15 Hz on that amp? If so, watch your mechanical excursion, or your next topic will be titled "My Q12 stopped working. . ."

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the port on the box that i built is 2.5 inches wide, seems pretty decent to me

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2" wide port is awfully narrow, I never go less than 3" wide on the port, but that's just me.

why is 2inch port to small?

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2" wide port is awfully narrow, I never go less than 3" wide on the port, but that's just me.

why is 2inch port to small?

I didn't say it was too small, did I?

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2" wide port is awfully narrow, I never go less than 3" wide on the port, but that's just me.

why is 2inch port to small?

I didn't say it was too small, did I?

well in a indirect way by saying awfully narrow, Im trying to have a box designed and just wanted to know, the prefab box i have now has a 1.75inch wide port

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that is one of my points but not in this post you can not calculate displacement before the port is calculated. so why use displacements in the formula? as far as i see it your adding to much air space with those calculators that add in the displacements. so why not just build a box like 2.5 cu-ft and stick a port in it and forget the displacements? all you have to do to make the bass note out of the port falter is make the box bigger yet ? it would be like using displacements.

I'm not adding any airspace. The displacements are subtracted from the volume and for reference the displacements I am talking about are like bracing(which there is none in this instance) and sub.

BTW just trying to figure out why your off of mine by .07 cu-ft mine say there smaller were your says it's bigger yet. could not figure it out but will sooner or later lol's

Your off because your calculating to much port displacement.

1. The physical port is only 21" long. So you have an extra .021ft^3

2. You are accounting for 6.25" of port wall that is not there. So then you have an extra .0352ft^3

So your 2.2795ft^3 + (.0352+.021) = 2.33ft^3 that I calculated.

you know what your totaly correct i am off. just do not use the re calculator that often so i was thinking that the port length was 22 long when it fell short a few :santa: any ways good point man.

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now im waiting for every thing to dry...i got carried away and forgot to take more pictures

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IMG_0285.jpg

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carpeted my box today wish i would make the port black

no more truck space but it bumps pretty hard

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4280328029_55e09d5bb4_b.jpg

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looks good! :drink40: x2 on the black port :Doh:

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