Fi Q 12" Ported enclosure design

[wkollmeyer 1]

Alright so I am trying to build a box for a Fi Car audio Q 12" woofer.

They recommend I build a box using 1.8-2.5 cubic feet @ 28-33Hz (32hz tuning is optimal, and has the most output and is still the most musical daily driving), and to use 12-16 square inches of vent area per cubic foot of volume.

I am talking to Chris at fishercustoms, and he is helping me design a box. I was using the RE Enclosure Calculator, and I'm not sure what he uses.

I gave him my max specs, 23" long x 15.5" wide x 16" high, and he came up with:

1.8 cu ft, 33 hz, 1.74" x 14" port ( 13.53 sq in vent area per cu ft)

When i put those dimensions into the RE ported enclosure Calculator, i got:

2.068 cu ft, 31 hz, 1.74" x 14" port ( 11.79 sq in vent area per cu ft)

His port size keeps his idea that a 1" to 8" port ratio is optimal

Now I am wondering if the RE enclosure calculator is correct or his? 1.8 cu ft seems so small with those large of dimensions. I trust his port calculations, but if that ratio is wrong, put your two cents in on what you feel is right.

If the RE port calculator is correct, then the port size is way to small.

Let me know what all of you think.

[shizzzon 461]

its been a long time ago since i "deboggled" the RE calculator but it is indeed wrong. There are things it doesnt account for and because of this, it's near impossible to properly calculate a proper box design.

[wkollmeyer 1]

so should i assume his dimensions are correct?

everything with his are fine except for the fact that when the sub is put in, the ported box will be only 1.64 cu ft....

[shizzzon 461]

he should be giving u NET volume.

NET means everything is accounted for, all displacements.

That's one thing the RE calculator cant do... is sub displacement. ALL box calculators volume calculation is done by NET only.

I'm sure 1.8cuft he is telling u is NET, not half Gross, hehe, you also have port displacement too.

[wkollmeyer 1]

very true. plus he emailed me back and said he uses winisd and autocad, which is the best way so i've heard.

hopefully the Q will still be able to hit the double bass just as well as the sealed!

[shizzzon 461]

Hey, he sounds like me!, exactly like me!

I use WinISD and AutoCAD as well.

CAD is so perfect for drawing out a design in your vehicle then being able to fit things in the drawing so u know exactly how to put them.

It's gonna be a nice design using that software.

[wkollmeyer 1]

would it be a bad decision getting this box built at a local audio shop? I want this box to be perfect, and as of right now I want BJ to build it (from fisher customs) but he has been on hiatus for god knows how long now.

I was going to have chris send me the exact dimensions for all pieces, and I will bring that to the shop and have them build it. I just don't want the shop to mess anything up.

[shizzzon 461]

he hasnt before has he?

I wouldnt trust local shop only because they may alter dimensions if they have their opinion about the design or charge ridiculous price if they have to built it to spec.

[wkollmeyer 1]

I am just anxious to get this box built.. I want to get it in the back of the car and listen to it!

When i brought my original design to the shop, and asked them to build it tuned to 32 hz and that size they basically told me to fv<k off lol. Which means that they probably will alter the design..

are there any other good box builders online?

[shizzzon 461]

besides the one u named,

Audible Customs

Thumpper

and that one guy Peter Kulicki, the mastermind of loud, hehe. He doesnt have a forum here.

[wkollmeyer 1]

how hard is it to build a ported box yourself?? bad idea?

[shizzzon 461]

not really, as long as u have a program that u can understand and find port area and length, and have a skillsaw, jigsaw or router with circle jig, powered drill, saw horses or equivalent, titebond, liquid nails, silicon and plenty of bracing if needed.

[JASON123 1]

I am just anxious to get this box built.. I want to get it in the back of the car and listen to it!

When i brought my original design to the shop, and asked them to build it tuned to 32 hz and that size they basically told me to fv<k off lol. Which means that they probably will alter the design..

are there any other good box builders online?

Do it your self it's not that hard or either get one of these guys to do it they are real good Audible Customs or Thumpper

[wkollmeyer 1]

haha yea about all that..

I just emailed Quentin at Audible customs to see if he would be willing to build the box for me if i sent him the specs.

[JASON123 1]

haha yea about all that..

I just emailed Quentin at Audible customs to see if he would be willing to build the box for me if i sent him the specs.

If you live in nc ill help you build one if you want to learn

[wkollmeyer 1]

No I live in CT... I just don't have the tools, and chances are good that I would mess something up with the bracing or dimensions.

[JASON123 1]

yeah no tools get expensive but the materials to bulid the box are not to bad good luck with your install

[wkollmeyer 1]

Will 1.8 cubes @ 33hz be too small for the Fi Q? I know that they recommend a minimum of 1.8 but will it be louder in a bigger box? Most of the videos I see of the Fi Q are in 2.2 or 2.5 cubes. I wasn't sure if those boxes would make the Q noticeably louder than a box at 1.8.