When I got home from the office yesterday, my wife had The Propellerheads cranked way up on the 2 Pi's; so her initial reaction seems to have tempered a little.

After several more hours of listening, I am now conviced that the "problem" I hear is indeed in the upper vocal range. Maybe a different or larger inductor than the .47mH Goertz copper foil I used is all I need. I was also thinking of trying the 1038 mated to a Delta 12-LF (in an appropriately larger box) for another experiment.