With any REL being used in a 2 channel system, the best results are with the supplied REL neutrix cable. This allows the subwoofer to receive & mirror exactly the same signal that the speakers are getting. This allows the REL subwoofer to blend perfectly with the main speakers. The RCA's are for 5.1 or greater home theater use allowing the LFE channel to be mixed more accurately with movie use. The end result is achieve the perfect 2 channel playback without sacrificing LFE playback for movies. At the end of the REL cable, there 3 leads & depending on the type of amp, there are a couple of configurations. I would strongly suggest contacting REL customer support for the right configuration. I have sold RELs and currently own 3 vintage ones on 3 different systems & they are connected differently per REL's recomendation.
