15 CompVR 4 Ohm The CompVR 15-Inch Subwoofer is a 4? Dual voice coil design, built for easy wiring. A solid pole piece and perimeter venting allows superb heat dissipation without breakdown and improved bass response. The Santoprene surround and progressive-roll spider keep the cone response smooth, linear and accurate at any volume level. The CompVR 15-Inch Subwoofer works best with a sealed or ported enclosure and 500 watts of recommended power. See below for more details.