J-Mac, Thanks for getting back to me, I appreciate it. More questions:
Where did you learn about combining port diameter and wall distance? If I understand you correctly, 2" from the wall would be better than 8" to get the most from the 170s on the low end, right? From what I've read, learning REW will teach me about and finding nulls (relative to sweet spot) but what about taming cancellation frequencies? Would 2" thick 12x12 suffice behind the 170s work for this? What is the rule for absorption behind bookshelf speakers? I do have a absorption/dispersion plan. Thankfully the L12 is generous above 80hz too and yes, two are for the standing wave issue (although the thought of four...
with two more 170s and a couple of boxes from miniDSP...
) Tweaker's delight, eh?