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ported box calculator

7.6K views 12 replies 7 participants last post by  Richv72  
#1 ·
Building a box soon for a single IDQ10V3D4, running on about 500 watts. Back corner of my 03 Jeep Grand Cherokee. Want to do a ported box, I've got about 2.3 cubic feet, gross, to work with. Shooting for a net internal volume of 1.3-1.5 cu ft. Not sure yet if I'll use a round port or a square/slot port. Made a living as a finish carpenter for over a decade, tools and skill are not a problem. Back and bottom of the box will be fiberglass to maximize volume over a complex shape.

Did something similar in a Toyota Tacoma 6-7 years back with guidance from Eric Stevens of ID, that setup was amazing considering the whole thing fit in a tiny space behind 1/3rd of the back seat.

What I need is a trustworthy calculator to help determine port size and length. And advice about port area and tuning frequency. And any other relevant thoughts...
 
#2 ·
Post the spec and I'll model it:)

I use bbpro, used to use Eminence designer which was a slightly watered down version so find it quick and easy to use. Winisd is very popular and free, though not played with it myself. Hornresp, free, can also be used, much trickier(IMO) but can do all sorts of weird and wonderful stuff-very powerful in the right hands, but I'm dyslexic and have a hard time visualising with it!
 
#5 ·
Thanks for the generous offer, but you dont want to do that for me. Reason is, the box back and bottom are going to be fiberglass with a pretty complex shape, conforming to the car interior. I'm building the thing as an open front box at first (bottom, top, sides and back) and I'll determine the depth of the thing after measureing the actual volume and decide what the port should look like. Whatever calculator I end up using, I'll probably run the numbers at least 8-10 times before the final panels are cut, and I just can't ask anyone to do that much work for me.

Are the12volt.com calculators reliable?


Subwoofer Enclosure Calculators, Fraction to Decimal, Parallel, Series, Port Length and Volume Calculators


I think thats what I used for my last ported enclosure, that one worked great.. Been too many years and too many beers to remember if thats the one..
 
#4 ·
^ RE's calculator doesn't allow you to change the length of your first port wall...so if you box is 18" deep internal, and you port is 3" wide, the first wall will ALWAYS be 15"...also, it seems to add in port end correction factor because I had it telling me a 15" long port, 6" wide had an actual port length of something like 26.75"

It only allows you to build one style of box...ported. I also don't like the way it lays out the pieces for the box design. The screen colors make it very difficult to read the numbers, too.


I'm starting not to trust it.

Jay
 
#8 ·
Is a 2x6" slot port, or a single 4" round port big enough for a single 10 with 19mm Xmax on 500 watts? I'm coming up with around a 24" long port for those size ports in a 1.3 cu ft box at 30hz tuning. Single IDQ10V3, that has the box right in the spec ID publishes. These #s are looking very buildable.

Also, if a slot port is not a straight shot, how do I make the internal turns? I'm picturing small 45 deg blocks at any turns, I'm thinking that I'd preserve the port depth when measuring at a 45 from the inside of the turn. This might sound crazy, but I've got a 4 year old who WILL cram toys and such into a port. To make toy extraction easier I want the end of the port traveling in a downward direction..

Fabrication advise welcome, please keep any parenting advice to yourself, lol...
 
#9 · (Edited)
Yup, all good in the hood with that.

Modeled in bbpro I get 4" ID port 28.91" long with a gross box volume of 2.208cf, no vent noise, SSF@ 18-20Hz

Regarding the bends-measure the centre line of the port for the length. 4" wide slot you'd measure down the middle, 2" from each side, for the total length, likewise for a round port.

EDIT: RE the parenting advice-my old store's boss had a 3-4yr old and he loved stuffing stuff into vented boxes. Ran into the showroom holding an apple, ran back out without it. I searched high and low for the apple and never found it; until a customer brought back a BP with and "annoying rattle"-I opened it up to find the dried out apple inside. MDF ring with some accoustic cloth over it should make an adequate vent grill!
 
#11 ·
I found french fries,happy meal toys,Lil hugs and my HU remote in mine.
After that I used that chicken wire with the 1/2 squares till they got older.