box design

i have an escort wagon and am trying to put 4 12's in the hatch but am having troubles with the design. what is a good gap between the box and the hatch? i am putting the vents facing the hatch and having the subs fire upwards to the roof.

any help would be great

I designed this system for four subs some time back for someone to fit into a tight space.  It uses two separate enclosures to make it easier to build them and put them in the car.  Of course, size specs can be changed to suit your sub/ box spec, but just for the principle of it, here it is:

Besides the "box-wrangling" factor, the benefits of this over a single, 4-driver upfiring config is:

• maximizes use of the available height of the hatch space
• reduces the gravity sag on the drivers
• allows for the combination normal/inverted look
• directs the waves toward the upper back part of the vehicle

But there is more effort needed to do this because of the difference in box volumes that are needed to be calculated because of the differences in driver displacement.  Wiring for the combination normal/inverted has to be thought out and executed properly.  And your woodworking and calculating skills have to be higher to achieve these angles.