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
My Cable Mart - 15ft 1 Wire SubWoofer 18AWG (1 RCA to 2 Pos/Neg Speaker Connects) Cable
RCA Male to Male Gold Stereo Audio Cable - 1.5Feet
Amazon.com: SHD RCA to 2RCA Subwoofer Cable Audio Cable 2RCA to 1RCA Bi-Directional RCA Y Adapter Premium Sound Quality Dual Shielded with Gold Plated Connectors-3Feet : Electronics
Premium Subwoofer Audio Cable 1 RCA to 2 RCA Y Splitter Cord Gold Plated 0.5~15m | eBay
Amazon.com: Mediabridge™ Ultra Series RCA Y-Adapter (15 Feet) - 1-Male to 2-Male for Digital Audio or Subwoofer - Dual Shielded with RCA to RCA Gold-Plated Connectors - Black - (Part# CYA-1M2M-15B) :
RCA Y Adapter Cable Subwoofer Y Cable 1X RCA to 2X RAC Audio Cable 1 Rca to 2 Rca Power Amplifier Audio Cable,1 Meter - Walmart.com