The speaker cone was successfully made lighter and more flexible than previous models, enabling it to be more responsive to the low frequency range. Produces quality sound even with the volume cranked up. Redesigned with a shallower edge structure compared to conventional surrounds, providing smoother oscillation at low frequency ranges than before. The CS-V4627 4"x6" speakers feature a durable woofer cone made from a mixture of Aramid, carbon fiber, and mica, along with a 1" balanced dome PEI tweeter that'll increase your music's clarity. These speakers will give you a solid boost in sound quality, even when powered by your factory radio. Grilles are not included – factory grilles are appropriate for most installations.