RCA (M) to 2 RCA (F) Stereo Audio Y Adapter Subwoofer Cable (24k Gold Plated) 1 Male to 2 Female Y Splitter Connectors - Walmart.com
Amazon.com: Poyiccot RCA Splitter Male to Male Cable, RCA Y Splitter 1 RCA Male to 2 RCA Male Stereo Audio Subwoofer Cable, 2RCA to 1RCA Bi-Directional RCA Y Adapter Cable - 25cm/10inch :