Okay, I'm building a box for my sub, but I need help. Because the box needs to be an odd shape, there are some non 90 degree angles. Do i need to cut the end's of the boards at and angle or can I just leave them at right angles and just fill in the gap with more sealant stuff? Also, do I NEED to carpet the box? I don't care what it looks like but I was wondering if it effects the performance.