their initial design, (meaning years back) was to be used sealed in the smallest box possible with great SQ and strong output, but after years of modifications and market changes, the now square L7's need to be more flexiable with enclosure, there were some issues with tinsel lead snapping, but from everything Polecat has said, that has been corrected with the 2006 models, at the moment I am not sure how they are designing the subs to preform, their SPL levels are supposed to be up from last year, but I wonder if they still are supposed to be best when sealed in a small box oh yeah, RL-p ftw