Bandpass Box too small?

Not necessarily. What type of bandpass? What size subs? What is the volume of both chambers?

The subs are two 12" KFC W3012 Kenwood, the box has the two subs mounted facing each othe at 45 deg angles in the center between plexiglass and then the outer portion has two ports in each side.  The box is approximately 16"x16"x36"

The box was definitely too small... I blew it apart built a new sealed box and couldn't be happier with it. The under sized box was robbing me of volume and sucking excess power.

welcome back, Lukie Light!  thanks for the update... i've been on the edge of my seat for... seems like weeks!  lol.  those subs are perfect for a sealed box, so hope all is good now.