Rca Adaptor Hi, I Hv An LG Active Sub With A System Cable (audio), Is There An Adaptor For An RCA Jack?

Hi, I hv an LG active sub with a system cable (audio), is there an adaptor for an RCA jack? - rca adaptor

I connected the speaker 5 lg (+ -) to my Sony receiver (high end), but as originally belonged to a receiving system hard drive, so that the cable system. Can be modified to adapt?