Sorry Rick,
English is my only language & I tend to get into short tongue on occasion, (in this instance short type perhaps?). Then again the sequence may be the issue - the 1st Q was for the thread author not by name but by virtue of his being the previous post; I subsequently addressed a Q directly to you, Rick.
Tracking as in tracking the progress of the studio being built.
Are you still writing songs is a Q for Supercreep & Incanus.
I know about the =Triangle & sweet spot stuff & have used it since setting up my 1st stereo (ah my old Silver from 1979 bought in my 1st year of work) let alone home studio. I was asking for elaboration on the 18" range at the apex. I asked for "your take" as I didn't want to be presumptuous & say/type anything that implied error or omission on your part.