what size port?

Your subs will play better, longer, cleaner, and louder if you go with a little bit smaller box roughly 36" x 14" x 18" using 3/4" mdf.  Using that box, i would tune it down to 29hz, which would mean using a 3" x 8 3/4" port.  You would have to split the box in two with a sealed brace if you want the port to be tuned correctly.  If you want tighter, more punchy bass, then you should reduce the size of your box.

well ive already stasrted making the box in shop class i got a 36 x 22 x 15.5 ... and almost done so what port can i do with what i got and make it slami want loud noticable bass

if you made it a 2 chambered box, use a 3" wide x 6.5" long port for each chamber

If you made it a single chamber, use a 3" wide x 2.5" long port

ok i want to get as much as possible out of these 2 twelve thats the goal so sshould i make it shorter.... one single chamber or two seperate chambers tell me what u think i should use

if you can put a piece in the center of the box to make it two seperate chambers, i would.  This leaves you some insurance incase you blow one of your subs, or if it becomes disconnected, the box wont have the wrong airspace for the working woofer. you can go ahead and leave the box like it is and just put that piece in.  putting that piece in will also help to stop the box from flexing, which makes the subs quieter, and can damage them.  one thing to make sure to do is to seal up all of the corners of the box.  Silicon caulk works well, just make sure to let it cure before you put your subs in the box, that way it doesnt mess up the woofer or surround.

well if u think its worth it i havent really started putting it together yet so if it will be louder 18 inches long i will d that. also i was planning on dividing it i have made plenty of speaker boxes im jsut new to the ported stuff

so if i make it 18 instead of 22 what port size do i need to make this thing slam......

sry for buggin u i just want to make sure

dont worry about it

Go with the box size being 36" x 15.5" x 18". Put a piece of mdf in the center of the box to seperate it into 2 chambers.  Use 2 ports, 3 inch diameter, 8 3/4 inches long,  by the way, what amp are you putting these on

i have a 900 watt rockfordfosgate would thos work