Okay, so here goes... I will probably purchase the Sublime Acoustic K231 Active XO. I would like your input on a total of 4 Preamps: Parasound Halo P6 (most expensive), Rotel RC-1572 MKII, NAD C165BEE, or Schiit Freya + (least expensive). I presently own ONE powered Sub-woofer (Polk PSW 505) and...