Coaxial 3-way speaker system: 6 x 9-inch (150 x 230 mm) woofer, 2-inch (51 mm) cone mid-range, 0.75-inch (19 mm) silk dome tweeter. The Evolution C2 systems deliver sparkling high-frequency detail, smooth mid-range, and powerful mid-bass, thanks to real silk dome tweeters and precision-engineered woofer designs. The C2-690tx system features 6 x 9-inch (150 x 230 mm) woofers with mineral-filled polypropylene cones, long excursion capabilities, and stamped steel frames. The woofer design benefits from JL Audio's vast woofer design experience and advanced modeling systems. The 6 x 9-inch (150 x 230 mm) format is a direct fit in many vehicles. The mid-range driver is ferrofluid-cooled, with a 2-inch Mylar cone diaphragm to smoothly bridge the gap between the woofer and the dome tweeter. Tweeters are mounted next to the mid-range driver and built with 0.75-inch silk dome diaphragms that deliver smooth, extended response, on and off axis. The small size of the C2 tweeter minimizes tweeter protrusion, allowing C2 coaxials to fit behind most factory speaker grilles. Woofer grilles are included, each consisting of a black grille tray with satin silver accents and a black steel mesh grille with an electroformed JL Audio logo. - Continuous power handling (RMS): 70 W - Recommended amplifier power (RMS): 15 - 125 W / Ch. - System efficiency: 93 dB @ 1 W / 1 m - System nominal impedance: 4 Ω - System frequency response: 53 Hz - 22 KHz ± 3 dB.