hey guys, im in the process of making a sealed enclosure for my new SE 15", i had the plans made up for the sub to be facing towards to front of the car or towards the rear, but after reading a few different posts for ext. cab trucks i am thinking about turning it into a downfiring box. i will need to add a few inches onto 4 of the boards to allow the box to stand without crushing the sub. my question is how much excursion do you think the SE will have w/ 600watts of power? i dont want to short myself and have the sub start hitting the ground, but i dont want it 5 inches higher than it needs to be. would an extra 3" prop the box up enough so the sub wouldnt touch the ground? thanks!