Receiver or Preamp

My answer seems uncomfortably obvious to me and I might not be understanding your requirements. There are many A/V receivers and pre/pros equipped with single ended and balanced inputs, the latest codecs with room correction, simply pick a price point.

HDMI resolves many issues not to mention the cost, clutter and any sonic influence that comes with analog cabling. Modern components using HDMI can calibrate the entire system more accurately than simply choosing a crossover point for the sub.

I was amazed by the ease and improvement modern room correction/calibration had on my awkward HT space. Another point I'm sold on is the 7.1 matrixing of 5.1 media.. 7.1 can make even small spaces sound large with a very entertaining surround experience. If the B&K sound speaks to you already then stick with it unless your able to audition other brands to make a more informed choice. Happy shopping.