Check the listing for details. Memphis Audio PRX124W 12" Power Reference Single 4-Ohm Subwoofer - 300 wRMS. Condition: New. Listed at 149.95 USD. Memphis Audio 15-PRX124 12" Power Reference Single 4-Ohm Subwoofer - 300 wRMSPower Reference Memphis Audio's best selling line of subwoofers is back and better than ever. The new black on black polypropylene dust cap steps up design element to a level never before in the line. Several performance enhancements including a high temperature TIL voice coil former, improved suspension and coil design and an upgraded reinforced spider shoulder elevate PR subwoofers to new heights. Audio enthusiasts respect Power Reference subwoofers for their reliability and performance and versatility. Power Reference subwoofers are a staple of the Memphis line. Proven performance and reliability is the reason Power Reference is our best selling subwoofer.