Best Buy: Infinity Kappa 12" Single-Voice-Coil 4-Ohm Subwoofer Silver 120.9w
Amazon.com: Infinity - Two Kappa 12" (300mm) 500 Watt RMS, High-Performance Subwoofers, Switchable 2 OR 4 OHM : Electronics
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Amazon.com: New Infinity Kappa 62IX 6.5" 225 Watts Max (75 Watts RMS) 2-Way Coaxial Car Audio Stereo Multi Element Speakers with UniPivot Tweeters with Oversized Voice Coils - Pair with Alphasonik Earbuds : Electronics