Port length? Where to cut?

[speedball1978]

flanges won't change the sound, it will probably change your tune...just use the flange on one end to mount to the box but here's a little secret, flare up the opposite ends using a torch or heat gun.. using a metal bowl and wala you'll have aero ports lol

I might be able to do that, maybe boil the pipe and try shoving a bowl or something inside of it to flare it out. Does 2 4inch diameter ports at about 9.5inches sound sufficient for a good box at 4.77 ft^3?

according to what info i'm getting from you, you're going to be tuned at 32 hz but you don't have enough port area.. you're going to hear alot of port noise and the box will sound like crap

my suggestion would be going with 4 4inch, or 1 8 inch pvc to gain enough port area in your setup

[trjohnst]

How much port area would I need with 2 4inch ports? I used psp-inc.com's calculator and found 9.5 inches. How long would my 2 4inch ports need to be?

[herbykw]

How much port area would I need with 2 4inch ports? I used psp-inc.com's calculator and found 9.5 inches. How long would my 2 4inch ports need to be?

9.5" from outside of flare to the end of the port. If you flare both ends of each port outside of flare to outside of flare. Put the subs and the port on the same side of the box. If you use those adapters as flares then i would sand them as smooth as possible and make it nice and make the airflow nice and smooth.

Edited May 9, 2011 by herbykw

[trjohnst]

This is why I am so confused, Speedball1978 said to put them on the opposite side and then I am told to put them on the same side.

But what you are saying is the 9.5 inches should be from the flare (outside of box) to the end of the tube (inside of the box). If it is done this way, then I have about a 10.2" long port.

So, my plan is to put them beside each other (about 1/2 inch apart) on the same side as the sub. So there will be 2 ports on the left of the sub (maybe a inch beside the sub).

I sanded the end of the port where I cut the tube in half, but I think sanding the inside is unnecessary because it would cause air flow friction.

[trjohnst]

Here is the box, I will be covering 1 hole and running just 1 15.