I have to figure out what size I have to make my ports. I have two 10" rockford forgate punch z's. According to fosgates specs, the bo volume can be anywhere between .75cu/ft and 1.75 cu/ft. And with my dimensions (32" by 12" by 12") I have calculated it to being 2.5cu/ft for the two after subtracting the displacement of both subs. Although I think I'm going to be splitting the two subs into their own enclosures, so putting in a sealed wall, which would then make it two 1.3cu/ft enclosures.
Does this all sound alright so far?
anyways, I have no idea what size I have to make my ports. RF says that the port should be 3" wide by 13 1/4" long for a 1.0cu/ft enclosure. I'd like to turn it somewhere around 35hz since that is whats recommended
what are my options here?
thanks everyone

 

somebody mu st know or know where i can find out.. i tried searching but didnt find anything

 

http://www.jlaudio.com/tutorials/ports/index.html

 

First of all download winisd if you want to start calculating port volumes.

For a dual sub setup it is easier to common chamber if you are using slot ports. The recommendation from rf is probably a 3 inch round port. I am not going to check the numbers, but from boxes I have built with round ports that sounds like a mid 30's tuning at 1 cube.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tOp shOtta &raquo;</TD></TR><TR><TD CLASS="quote">http://www.jlaudio.com/tutorials/ports/index.html</TD></TR></TABLE>

I've already read this site before, although I just get confused reading it, lol

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by vteg &raquo;</TD></TR><TR><TD CLASS="quote">
For a dual sub setup it is easier to common chamber if you are using slot ports. The recommendation from rf is probably a 3 inch round port. I am not going to check the numbers, but from boxes I have built with round ports that sounds like a mid 30's tuning at 1 cube.</TD></TR></TABLE>

I think i'm going to be using round ports for this setup. and yeah, rf does recommend a 3" in diamerter port. Although they recommend 13 1/4" long ports, although my bo is only 12" in depth, so they just wont fit. I was just wondering if maybe just making the port 10" long would make that much of a difference?? Or if there was some other way I will have to do this(ie. using elbows so I can make the port 13 1.4" long)

 

You will need to use winisd or some other program to calculate the tuning. Take the box internal volume. Subtract woofer displacement (.1 cube is a good assumption for a 12), and port volume. That will give you the box volume. Then you calculate the tuning frequency off that volume with a 3 inch round port at 10 inches.