I'm running the Hexes actively, so that's 65W/speaker (130W overall per door). I would think that's plenty of power to drive the D971s.

The Hexes are supposed to be good to 43Hz (or so), so I run them 63Hz/12dB with no clipping and plenty of low end coverage to blend with the sub (crossed at 50Hz/12dB).

I run the 4KHz x-over for the highs/mids because...well...I was talking to the owner of Zed audio and that's what he suggested as a good x-over point. While the tweets will play fine down into the 1-2KHz range, I'd like to think it helps limit how harsh/bright the sound is to have the woofer playing that range.