Amazon.com: DS18 SLC12S Car Subwoofer Audio Speaker - 12" in. Paper Glass Fiber Cone, Black Steel Basket, Single Voice Coil 4 Ohm Impedance, 500W MAX Power and Foam Surround for Vehicle Stereo
Amazon.com: PRV AUDIO 12 Inch Midrange Speaker 12MR2000 2000 Watts Program Power, 8 Ohm, 4 in Voice Coil,1000 Watts RMS Midbass Woofer for Pro Audio Systems (Single) : Electronics