■ Vented Subwoofer. ■ One 18" high powerful subwoofer with 4" voice coil ■ Firm grille with perforated hexagon steel protecting the loudspeaker from outside force impact. ■ The enclosure uses high-density plywood and firm finish to protect it from friction and collision. ■ Acoustics buffer, high safety and sound quality ■ Pole inserting type, convenient and swift for installation. ■ LF is deep , durable and strong ■ Used in local needing powerful LF energy compensation. ■ Combining with DR68 series, working in the small/middle scale sound reinforcement system.