You probably need to use RCA cables to connect the head unit to the line out converter. The fourth input includes a scaler to support both video and computer resolutions and also supports analog RGB and component input so older devices can be used as sources without the need for external conversion equipment. Pyle 8 1600w Dvc 4 Ohm Car Audio Subwoofer Speaker Set 2pk Plpw8d In 2022 Car Audio Subwoofers Car Audio Subwoofer Speaker Adjust the Input Level switch to match your input. . Run the blue cable to the amp on the opposite side of the vehicle. The included 10 input harness has a Molex plug on one end and female stereo RCA jacks on the other. Some single-din head units come with a slot for a line converter directly underneath it. However you may also encounter a subwoofer using RCA or wired stereo connections. When using a speaker level input cut the RCA jacks off and splice into the remaining wires. The VR-4HD has thre