My receiver does have a Sub-out, but at the time I wired my system, I didn't have a good RCA sub cable, so I wired my speakers to the sub then back out to the speakers. When I wired a generic RCA I found lying around, (Not a cheap Radioshack one, medium thickness; 14 guage?) the sub was a lot quieter. it only achieved normal volumes with the gain maxed. The Onkyo receiver doesn't have sub out volume adjustments. Any ideas why it's so quiet? It sounds pretty good, but would it sound better with an RCA?