Kevlar-impregnated paper woofer cones - This combination has been chosen for its high strength-to-weight ratio, and is formed using a proprietary manufacturing process. Besides improved transient response, this cone adds stiffness to relieve stress concentrations that may accumulate at the base of the cone under high power and high-pressure applications. Plus One (patent pending) woofer cones - JBL has taken its incredbile Plus One cone technology into the world of subwoofers. Each Power Series sub features more cone area than that found on competing subwoofers of the same size. This increase in cone area delivers an audible increase in bass output and efficiency. The JBL P1224 features a proprietary die-cast frame that ensures that the motor structure stays centered in the voice-coil gap, ensuring long-term reliability and durability. Stitched-in tinsel leads are used to greatly enhance reliability and eliminate audible tinsel lead slap.
