how do i know if i have enough port area?

[adidasxp17 0]

hey guys, I have a wedge box that goes behind my bench seat in my truck. its about 2.8ft3 before sub and port displacement. right now i have a 4in round port that is about 7-7.1in in length. so that puts me at about 35hz tunning wize. however i just upgraded my amp and bought a SSD. so i want to mkae sure for port is good. i will be re tunning to about 33hz so that will make my port longer. however should i upgrade to a 5in round? i dont know much about what would make a good port. i thought as long as it was tuned to the right hz it didnt matter. please offer any advise. i cant wait for the SSD to get in!

[sefugi 166]

I use this site as a good reference: http://www.carstereo.com/help/Articles.cfm?id=31

[adidasxp17 0]

I use this site as a good reference: http://www.carstereo.com/help/Articles.cfm?id=31

when i enter my box volume, should i account for sub displacement, or just the raw numbers? and what about port displacemnt, is it taking into account port displacment already?