Component speakers - crossover freq

I have been looking to get MB Quart components.  I noticed that as I climb up models, the crossover frequency decreases.  For intance - the low line Discuss series has a crossover point of 4500Hz, the next model up (Reference) has a crossover point of 3700Hz, and the Premium line has a crossover point of 2500Hz.  Why is there such a big difference between the different models?  Wouldn't I get better midbass with a higher crossover point? 

The reason for this difference is range.  The higher models have more acoustic range and a highr price tag.  Mid bass depends on models not the frequency ranges listed. I have heared low range mb quarts have more mid bass than the higher models, just like diamond audiomatrixman