from what I remember reading, mid bass is the hardest range to reproduce inside a cabin, I need to add some mid bass to my truck, because I have a large discrepancey between the pair of 5.25 RF FanQ comps and what ever sub I have in that week, for my listening tastes, and many others on here, try to keep our subs crossover at 80hz and below, and I try to keep my subsonic freq away from my components, so there is a dead spot in my truck between approx 300hz and 80hz, thats where the mid bass would come in to help reproduce those frequencies, I hope that helps explain it a little from my perspective