Need help with a few questions

[OneBad9D5]

I have this sub:
http://www.cardomain.com/item/POWMOFO12

and its going to be powered by this amp:
http://www.cardomain.com/item/POWA1800DB

Ok now my questions. I am going to be building the box where my rear seats are because the box has to be a 2.4 cu. Ft. This will be my first attempt at a ported box and I have to have two ports and the ports have to be 3"x6.75" Now, it says the ports have to be tuned to 40 hz, how do you tune the ports? I tried searching but couldnt find anything.

Also would it be a good idea to put the magnet outside to make it more show quality or will it ruin the sound of the sub?

I had some more questions but my mind went blank so I will ask them later when I think of them. Thanks.

[96firebird311]

A box is tuned by varying the length of the ports. The longer the ports the lower the tune and vice verse. Before deciding on a tuning frequency, I must ask, what are you looking for from this sub? What type of music do you listen to most?

Where did you get those port #'s from? A single rectangle shaped port would be far easier to build and far more effective. Go to www.linearteam.org and download WinISD Pro. This is a box designing program. It's pretty basic really. Go to database editing input the T/S specs of your sub. You can get those off the PA website or maybe from your owners manual. Play around a bit and you'll learn a lot.

Or if you want to wait until Tues when I get back home, I'd be more then happy to do it for you. [img]smile.gif[/img] Either way, DO NOT rush and build the box unless you're certain of what you're doing. Damage to your subwoofer is possible. You want the best? Then take your time.

[OneBad9D5]

Ok I will take a look at that. I got the port numbers from there website and from the manual I got with the sub.

I will be using this sub for mostly rap music and will want it to hit hard.

It will be about 2 weeks before I build the box I still have to get a Cap and a new car battery.

:EDIT:

Here is a quick copy and paste from there website.

MOFO-12

* 2400 watts power
* 1200 Watts RMS
* 270 oz. magnet
* 3” BASV/Kapton Hybrid 18 AWG Voice Coil
* SPL 90 dB
* Fs: 36.7 Hz
* Vas: 0.73 cu.ft.
* Qms: 5.34
* Qes: 0.36
* Qts: 0.3363
* Xmax: 0.7"
* Sealed box: N/A
* Ported box: 2.4 cu..Ft.
* Tuning: 40 Hz
* Port size: 3”(dia)x6.75”(length)
* # of ports: 2

[StrtRacer98]

a single rectangular port isnt a port, its a Vent.
a port is a circular hole in which a plastic port in depth controls the tune of the box in Hz