The XLS will easily play down to 50hz (or lower) but sounds terrible above 250-300hz. The B&C will not play down that low but will play up to 700hz or so. The B&C is basically a pro-audio driver with high efficiency and low Xmax. The XLS is a home audio driver so it is less efficient with more Xmax. For a pure midbass, the XLS is a far better choice than the B&C, in my opinion. I needed a midbass/midrange to mate with a pair of horns so the B&C was the better choice unless I went with a three way front stage. Hope that helps, any questions let me know.