Joseph,
as I mentioned in my earlier response you should keep your main speakers connected to your amp as you have them, then run a second set of speaker wires to the REL subwoofer. You will get the best sound reproduction keeping your main speakers connected directly then add the sub, you will need to spend some time setting up the sub, crossover frequency and level matching.
Some time and patience will have you very happy with the great bass added to your existing system.
Gary
as I mentioned in my earlier response you should keep your main speakers connected to your amp as you have them, then run a second set of speaker wires to the REL subwoofer. You will get the best sound reproduction keeping your main speakers connected directly then add the sub, you will need to spend some time setting up the sub, crossover frequency and level matching.
Some time and patience will have you very happy with the great bass added to your existing system.
Gary