Hi my subwoofer is a RE SX 15 which displaces 0.22 cubic feet and my box dimensions are 10" high, 20" long, 36" wide. I purchased http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=268-352 two of these for my ports and i would like it to be tuned to 35 hertz. i dont know exactly how much bracing i will be using but i will be bracing the entire front panal for sure and it is going to be made out of 3/4" mdf.

Im thinking that i will have the sub facing upwards with the ports in the bottom middle of front panal unless someone has some good suggestions otherwise.

I know its not the best box dimensions but i have a 2005 sunfire and the trunks are really a pain in the *** for putting a decent box in.

 

i dont know the calculation how to get port legnth/hertz and how to calculate the flared port area can anyone help me?

 

You need about a 17" port and you will be tuned around 35 HZ. HOWEVER, you should reconsider your box. You will probably see better results if you have the box sitting against the back seat, firing towards your trunk. This works best with your ports firing towards the trunk as well or you can have them firing to the side if you have to.

 

i have an amp rack made from 1" partical bord along the back seat and it creates a wall for air to bounce off. my current sub box works better firing towards the seats than the trunk. the trunk shakes too much

 

i have 2 ports is it 2 17" ports?

 

Yeah each port should be 17".

 

Put your box all the way back into the trunk facing into the car or seal it off from the trunk. Loudest possible scenerio with those vehicles.