Many thanks for the math lesson. There is nothing more humbling than trying to figure out electronics on the Internet whilst everyone and their brother can see you make mistakes.!!
The latest and greatest attenuator circuit was built last night. Early listening in the basement system sounded ok with a tad of rolloff of the high frequencies. It is in the basement system cooking for the day and we'll see what it can do tonight in the main system.
Thanks for all the help!