The only mistake you made was using 4x4 as your radius squared. The pipe is 4" in diameter therefore the radius is 1/2 of that or 2". So, Pi (3.1415) R squared (2" squared= 2x2) to give you 3.14x2x2=12.56 inches square, instead of 3.14x4x4 (which you had). If you re-calculate with everything else the same as you had it...you'll get the same answer as we did. The box dimensions you can adjust as needed and I agree with the other guys as far as adding another port if you can (should be able to now that you have more space to play with).

 

Ahhh... thanks a pile prof Veeman There's hope yet for me

JD -- yeah 5.6 isn't enough port is it, I was thinking 3 ports would look crappy anyhow, I'll try to figure out a dual 6" or triple..

Thanks for the confirmation Jalat

 

are you guys sure that's not enough port?

i had a box that was very similar. 3 12's and three 4 inch ports in a box that was about 4.5 cubes - 154's all day in a full size suv

dont worry about port displacement when using 4 inch aero ports, you are only making a simple proccess more complicated.



it was actually louder than a similar box with 4 ports that was a little bit bigger and had another 12 in it.


go for something like this,

 

Now that I know have a little more space, the box is now meant to be---
2.0cuft per sub at 34hz

The PSP calculator shows for 6 cubes at 34 hz as 2 - 6" 18.5" long flared ports, or just a little bigger than the port kit is, I think using the kit as is, will simply raise the tuning just a touch? But I'd have much more port area... like approx 54", which would be around 9" pr cube? I think I have the math now...lol And that seems like an easy build

Yuli...so 4.5 cubes with 3-4 inch .. would be the same as 6 cubes with 4-4"?
I guess I could put two on each side with 4 inch ports, but I'm not a fan of soooo many ports. How would I calculate the curved wall in the box? That looks useful!!

Tough decision.. I could use some more info
In the maybe not so distant future, when I do increase the power, say to 4-5k .. and I wanted to use this box....
Would I be better off with the small ports or large?

 

easy on the calculations man lol. dont worry about calculating the curved part.

with aero ports you can fine tune the box by ear by making the ports a bit longer or a bit shorter. you can tune the box exactly to your liking even after everything is finished. with aero ports there is no need for massive math problems as you can fine tune at any time afterwards.

my boxes were a bit on the small side cuz they were SPL oriented, but even when i stuck long ports in them and hammered them with 5-6k of power it was retaaaaaaaaarded on music.

u can go 4 ports also. just for me 3 always worked better. you could make a box with 4 ports and if you dont like it just take one out and cover the hole.

 

k man.. I'll turn off the calculator..Good thing, you can see how good I am at math.
I had not thought much about changing the box after it was done.... I was just gonna pray to the audio gods...
but yeah, I guess the PSP ports are simple to change/tune huh.

I think I understand enough that we can at least make a box better than the prefab we have. Thanks guys..

The proposed shape of the box, 48x17x17 makes using the 18" long 6" ports tough - either have to use bends, port out the sides or have some port sticking out. plus the kit is already 1" shorter than I need
The 4" ones would fit in almost any config. and I would have lots of extra length if needed with the kit

I'll choose and get building soon.

 

post up pics when u do.

 

Yuli- Is that curve, a piece of sonotube? dang I had though I would have to be bending and glueing 1/8" plywood together. Glad I noticed...

 

And pics of you cutting and gluing all those pieces of wood would have added immensely to this thread's entertainment value.....

See you and "just your bro" in Barrie....

 

lol...yeah it would be a hoot, I'd probably end up with one stuck on my forehead

But I bit the bullet and pick up about a litre on resin and hardener. Not looking forward to applying it, but I'll be pleased if it comes out good.
Also came up with a neat idea for the box, convertible... groundpounder to bassracer , or maybe plain to crazy(for street vehicles anyhow) in 5 minutes or less...lol ....but you'll have to wait to see that idea

We'll see ya there Red.
Someone order a hotdog cart!!!