PR9603IS Features:True 4 ohm ArchitectureLow impedance voice coils make the most of power from the amplifier for stronger clearer sound.Plus One™ Woofer ConesUp to 35% more active radiating surface area creating powerful accurate exciting bass.Vented Motor AssembliesMotors run cooler for greater durability and less mechanical noise resulting in better bass response at low frequencies.Plus One™ Woofer ConesHarman’s patented (US patent #7548631) Plus One™ polypropylene cones provide more overall speaker-cone area than other cones in its class — the result is higher sensitivity increased low-frequency output and greater musical character.Edge-Driven TweetersSoft dome tweeters deliver a smooth high-frequency response and an increased power handling for highs and mids which equates to more lifelike sound from vocals cymbals brass instruments and pianos.Frequency Response Up to 21kHzHear what you’ve been missing — the Infinity Primus Series offers a frequency response that delivers the full-range response associated with exceptional sound.Individually VoicedFor most brands off-the-shelf speakers and a cursory approval of frequency response curves are good enough. That’s not the case with Infinity the world’s top-selling car speaker brand. They don’t only listen to their speakers against the competition — they voice them against each other to ensure each line has the consistent Infinity sound signature car audio enthusiasts have come to know and love. This is just part of an extensive development process undertaken by some of the best transducer engineers in the world to provide the finest listening experience at any price point.Two More Configurations to Fit Most VehiclesThe Infinity Primus Speaker Series are designed to fit most vehicle speaker openings without cutting or modification. Simply put it’s the easiest way to boost your car’s sound performance.Affordable PricingThe Infinity Primus S