I have a Rel Q150 connected to a Marantz SR5200. My Speaker settings are Front: large, Center: large, Rear: small, Sub: yes, Center rear: no. Do I need the XLR cable connected to the speaker terminals on my reciever, to let me hear bass that the speakers (B&W 602S3s) cant reproduce, considering bass management in the reciever, or is the cable just going to "double up" the bass so I get the same bass going into the sub from both (high and low) inputs? Without this cable connected, I can still get bass through the subwoofer when playing CD's, but I don't know what the frequency the LPF in the reciver is set to output to the sub, and I don't know whether that with my fronts set to large it still outputs bass through the fronts or does it cut off and redirect to the sub, or am I getting the same bass out of the fronts and the sub? In source direct mode I don't get bass out of the sub with CD's (as expected), in which case i'd have to use the XLR cable from the speaker terminals to the high input on the sub.