face to face the speakers will start to cancel out......by the time one bass note sound wave is coming back towads the speaker after it hits the trunk, the next note will distort the 1st one......wit the speaker at an angle, none of the bass note will come in contant with another...they will just keep passing along

 

so angle the speaker down toward the floor of hte trunk or angle it up toward the top of the trunk, or do i angle the backside of the box when i make it??????????????????????????

 

it is easist if you make a slant front box.....
basically, just dont face a sub directly at the trunk....

dont do it like this if you have 2 subs....
__________trunk lid

__ __ speaker front

do it more like this if you have 2 subs

__________trunk lid

\ / speaker front

 

speakers face to face is called isobaric. One speaker is wired the opposite of the other one. The pro on this cuts the box space in half. But looses 3db compared to a normal box set up with two speakers. And I can on and on about different boxes from 5th order to 8th order and so on. Some boxes will hit twice as hard as some using the same speaker.
Back to in the trunk you do not want the subs to be facing head on to a hard surface. Or the reflection sound wavewill cancel the original sound wave from the sub.
If you are facing your subs to the rear. The reason it seems to hit hard is because on some frequencies the original and the reflected frequencies help each other alone. some of the others are canceled. In which you will have a narrower frequency band. ( best way to test this is to get a test CD) Play the disk with the box one way then turn it around if posible.
Kind of think of it like this. Have some sit across the room. You stand in the doorway facing in to the other room. Talk to them without yelling. Then turn around and speak to them again they will hear you better and clearer.