help with cancellation

I just installed a tempest in my 97 mustang to hold me over until my b12 gets here. 5.25 cubes before disp. running off of a ca600. The sub is firing up towards the back of my trunk and I have a huge port firing into the cabin. I have some major cancellation because with the trunk open it SLAMS and has very good sq very low. With the trunk closed its a little bit more then half as loud with distortion. I know the problem is cancellation, but how do I solve it. I was thinking to seal off the box to the opening of my trunk so I only get waves from the port. The other solution I had was building sort of a wall that extended up from the back of my box (near sub) and building walls on the side then covering the top to direct all of the waves from the sub striaght to the cabin without letting any get into the other parts of the trunk....thanks for your input.

It's usually best to keep the sub and port(s) on the same side, otherwise you may run into cancellation issues. I'm wondering how in the hell you managed to get that box in there, given the typical size of a Mustang trunk... I'm assuming there's no way to re-arrange the box in the trunk as-is... Is it possible to relocate the port?

32x30x12.5 will slide right in if you take some stuff off and go through the back seats. but this was the onl way the box was gunna work.

increase or decrease the space between the subs.
what this will do is change the freq. of the holes being produced. the trick is to get the holes in a low enough freq. where you can't hear, or in a high enough freq. where your mids can fill

It don't matter now I got mad at that install and ripped it out!! I'm gunna run a shiva instead untill my brahma gets here.