1. Makes sense that all processing increases THD+N. I am still curious then (not questioning), why reply solely on PEQ and not use auto room correction?
2. I labored for hours (and hours and hours) with REW for placement and treatments so ARC only tidied up things, but it did make a measurable difference in flatting the FR, admittedly I don't know if it is an audible difference....
3. Anyway, I know I could simplify things a bit, and open my options for other products that are digital-only, if I would throw in the towel on my current 2CH config, but I am not sure what I gain…