instead of using a predetermined crossover point and slope that might not work well to match your vehicle acoustics along with not having the ability to adjust the midrange and tweeter levels nor time align each independently aka passive crossovers, the ones you see in component sets. You use a DSP or Active capable head unit so you can perfectly match your vehicle acoustics, put more power to your mids and tweeters, Achieve a proper soundstage now that you can time align each mid and tweeter individually and overall achieve a much better blend between mids and tweeters.