If any of you are familiar with REL, Sunfire and Quad please help.  I am looking at a REL Q 201, Quad L subwoofer, or Sunfire True subwoofer.  I have Quad 12L as my mains, and will eventually get the 22L, I have a Marantz SR 7400 receiver and use audioquest interconnects and speaker wire.  I want to know what sub would go best with my speakers, would a different brand, or the matching sub go best?  If anyone isnt familiar with Quad L series, check out iagamerica.com , then go to Quad and click L series.  Also, if I place it behind how should the Phase be? 0 or 180?