help getting the Low Lows

[hammerhead-ky]

Yeah a leaky sealed box i've heard that and understand it, i feel like making the port smaller for lows would be backwards . if your moving more wind youd need more port area to let that air escape. but i know very little about the way subwoofers actually function. i have a problem. i need professional help

also more power, not right now no. just not in my budget i have to get a new vehicle to put a bigger alt on and i think 2k is probally the limit ill stay at with stock alt.

[hammerhead-ky]

in the car its djjd decaf got160s ultralowmusik djdb djsnt etc. i like regular music too but i listen to that type with headphones or in the house. i just hope someone who's done this before can educate me lol.

[ShadeTreeMechanic]

If you want it to be loud, you need a big box with a big port. Also it depends on the sub. I am not familiar with your sub, but I do know that the roll off curve on the bottom end for the 3db down point is calculated from the Fs parameter. So tuning below the Fs will most likely result in the port tuning being below the -3db point causing output to suffer. The port will need to be huge to even have flat output.

[hammerhead-ky]

ehh the definition of loud is quite vague anyways, i understand my 15 hz isnt gonna be nearly as loud as the same setup tuned higher at 40 hz i just want it to play it with some authority and no unloading/bottoming out issues

[ShadeTreeMechanic]

Playing 15hz will be about impossible to hear due to the ears efficiency below 30hz falls off rapidly. What you are talking about needs tons of power. You could do it with what you have and it might shake the car a little, but it won't be very loud.

[hammerhead-ky]

I know im risking the money and time of building a box that ends up wasted, theres always a risk. I am going to go for it though ive seen some pretty nice setups around 2k tuned ultra low do pretty well. i want to feel it. theres no way im not trying it lol. i just want to have some help from people who have done it before or atleast know how to do it so i can have a better chance at success

[ShadeTreeMechanic]

Make sure to post pictures and let us know how it turns out.

[hammerhead-ky]

I certainly will whatever happens hophally my mistakes or success can help somebody else too lol

[zxsonnyxz]

Not considering bandpasses etc:

I find slotports to be the best with low tuning, cause you'll almost allways need bends and stuff.

And you need some port area for that box, if you're too low you might as well run a sealed box as mentoned.

You probably need to tune at or below 20hz for that kind of lows, the roll-off is very steep for every hertz down low. Also think about using the distance to your rear hatch to your advantage for an extension of the port. I had a box that played and maintained in controll at 15hz, tuned to 18hz so only 3hz below tuning (not car audio). For loading off the rar of a car that tuning could be raised a bit and still go as low I believe.

I say go for it and see the results for yourself, go just a little small on the port but make sure its smooth and even inside with no sharp edges. Two 12s should have reasonable output even for this.

The only problem I see, you might lack the space to make it how it should be.

I don't have specifics for you right now just theese general thoughts:)

[hammerhead-ky]

I think your right on the just go for it. im gonna have to try several things to get it right more than likely. first thing im gonna do is attempt 4.7 port area per cube tuned at 20