what type of port is best?

I will soon have 2 audiobahn AW1206Q subs and i would like to put them in a ported enclosure. I would like like to know if a round or a slot type port would work best. The spec sheet shows the recomended round port diamentions, two 3"wide by 8.5" long. Can i take the volume of those ports and just make a slot port that has the same volume?dak

you can take the AREA of the port opening and use that area for your slot at that length. If it shows 2  3" dia. ports per woofer then you will need to either costruct a box with divied chambers and 2 ports per sub or one big box that is double the size for 1 woofer and use 4 ports.  You can use the same port opening area in a different shape as long as you keep the length right.  For instance if you need 2   3" dia. round ports that are 8.3" then you could also use 2 slot ports with the same port opening area 8.3" long.  You need to use the old   pi * r ^2 formula.  You can't add port opening area and keep the lenght the same, it doesn't work that way.  I hope I made sense.