I have a Pioneer a30 amplifier with wharfedale 122 speakers. I would likemore bass therefor i'd like the addition of a subwoofer. I was thinking of purchasing the wharfedale diamond sw150 sub, is this completable with my existing system bare in mine my amp does not have a sub out. Can you please advise me as I have been trying to research it but with no luck. What additional wires do I need and how does it get connected up?