Need help porting my box.

I've got an Atrend box that completely fills the space behind my back seats with two 10"s. I want to port it but I don't know how big the hole should be or how long the tube thing should be(the box is only 8" deep. I want to tune it for the lowest frequency possible. Thanks and sorry for the newb-ness.

 

Never mind. I found a port calculator and figured it out. The box has 1.125^3 feet and I found a 2.5"x4" port tube so it'll be tuned for 36hz.

 

If you use a single 2.5" port for two tens you're asking for trouble. That box will huff and puff like a mother fucker. You'll need a larger port diameter for sure. I'd say AT LEAST two 3" ports for it. Unless they're wimpy tens. If you give me the specs of the subs I could figure it out.

 

Each sub will have it's own port.

 

You'll need at least a 3" port I believe. At higher volumes you'll hear the noise from the ports. And how did you settle on a 36hz tuning frequency? I'm assuming this was specified or calculated from the subwoofers specs?

 

I used a calculator for the frequency. With a 3" hole i won't be able to use a long enough tube. Either way, It'll still be better than being sealed.