I have a design already for my 15L5's. Doing 2 individual boxes, 6 cubes @ 30 hertz, with 73.5 inches of port each. I love low bass, and I doubt I will be able to pull the hairtrick but that would be pretty sweet. I hear that with walls you need to tune lower to pick up the low end compared to rear/upfiring, is this true? Or would I be better off tuning higher and still be able to pick up a fair bit of low end. This is all daily driving, no comps. If I should change anything, let me know what you think asap, as I am cutting my wood tomorrow night.