Subwoofers with RCA line input

RCA (line)

— classic line input with RCA connectors used to receive the signal from the preamplifier. One connector in this case is responsible for one channel of sound, so there are usually several RCA jacks — most often two (for stereo). The difference from a similar LFE is that the line interface is designed for a full-frequency signal, and not just for low frequencies. The presence of such an input simplifies the connection of a subwoofer: not all audio equipment has specialized LFE outputs. However, in some models, RCA is only responsible for signal switching to other speaker components.