As long as the box volume remains the same, you can generally change dimensions slightly with no noticable difference. If you wanted a box that was 14" wide instead of 16", then you'd need to make the cabinet be 14 7/8" deep. You might make the box be 13" wide and 16" deep. That way you wouldn't have two dimensions so close to being equal.The thing you want to be careful of is moving dimensions or positions around vertically. The height of the box and the vertical spacing of drivers should remain the same. These are critical dimensions chosen to minimize response abberations from internal standing waves.