Thread: connection from car pc to amp

A sub amp just combines the incoming L and R signals to a mono signal. The sub output on the sound card has already been combined for you. I suppose you could just plug it in to either the L or R input on the amp, but I'm worried that leaving the other input floating would introduce noise. So you could either use a splitter, and feed both inputs, or get one of those little plugs that shorts the center pin to ground, and plug that into the unused input.