The Pioneer TS-900M 4-way, 6" x 9", 450 W max power automotive loudspeakers feature Pioneer's OPEN & SMOOTH sound concept that provides a seamless and smooth transition between the woofer and midrange/tweeter drivers to deliver uniform off-axis frequency response optimized for automotive applications where one or more speakers are often aimed away from the listeners' ears. 18 mm and 11mm Super polyethylene terephthalate (PET) hard dome tweeters paired with a 2-1/4" cellulose fiber cone midrange produce clear high and mid frequencies while the 6" x 9" carbon and mica reinforced Injection Molded Polypropylene (IMPP) woofer cone delivers deep, rich bass with low distortion, even at high output. Included multi-fit installation adapters optimize fitment in applicable original equipment (OE) speaker locations, making installation simple and easy. Pioneer's free CarSoundFit app (downloadable on the Apple App Store and Google Play) provides a virtual listening demonstration of these and many other Pioneer car speakers, allowing you to compare between your original speakers and the TS-900M speakers.