ok so im building my first sub box for my 10" clarion Clarion PXW1051 the specs says it needs 1cubic foot for ported box and a 2-1/2 x 11-1/8 port to get 31htz im using a calculator on http://www.hometheatershack.com/foru...me-calculator/ and making a triangular enclosure ive entered everything with my dimensions and driver volume and port volume and it says i get 1.018 cubic feet of space. The problem is with the port, i was planning on using pvc but they dont have 2-1/2 wide pvc so im not sure what i should do.. could i just use 3 inch? i used a round port calculator and it said if it was 3in it had to be 17.2in long. would that give me the same effect? or is there any other solutions so i can get 31 htz with a tube like multiple ones? my box is 21 wide top depth is 9 the bottom depth is 11 and the height is 14. thank you ive been searching for a few days and cant figure out what to do this is my first box

 

You can be flexible with the port. Port size isn't the real concern, it's the resonance. You have already found that there are port calculators out there, and they are useful for a very good reason: The air in a port (based on the diameter/length combination) of any port has a resonant frequency, and there are a nearly infinite number of diameter/length combinations that will yield the same resonant frequency.