The C2-570x system features 5 x 7 / 6 x 8-inch (125 x 180 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. Tweeters are coaxially mounted 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. Grilles are not available for this speaker system.