slots on my enclosure???

[slicks5150]

the box on the right hand side from the top view shows where the slots bend do I bend it to the center of the slot and stop there. and what is the purpose of the bend. do I need it to turn out like in the picture ? you can click on the picture for a larger view.
http://img98.echo.cx/img98/535/boxes21tr.th.png (http://img98.echo.cx/my.php?image=boxes21tr.png)

[bcarpenterfhl]

the purpose of the bend is to extend the port length.

[slicks5150]

so if my port will be 17.71 inches , and the box is deeper than 17.71 inches I would not bend the slot board? just make it straight ? should the distsnce from the back wall be the same to the board as the width of the slot vent 1.75"
http://img100.echo.cx/img100/7945/slotsnotbent8aw.th.png (http://img100.echo.cx/my.php?image=slotsnotbent8aw.png)

[bcarpenterfhl]

exactly