The Pioneer A Series speaker sound design purposely matches the subwoofer and full-range loudspeakers to provide seamless and smooth sound characteristics with dynamic, high impact bass that lets you hear and feel the music. Pioneer's OPEN & SMOOTH sound concept provides a seamless and smooth transition between the midrange and tweeter drivers and delivers uniform off-axis frequency response optimized for automotive applications where one or more speakers are often aimed away from the listeners' ears. Included with this Pioneer A Series 6.5 In. 2 Way Component Speaker System are multi-fit installation adapters and tweeter mounts. These expand flexibility and improve acoustic performance. And with the integrated inline crossover network, you increase installation flexibility without the need of an outboard module!