I think @jond has made the best contribution to the discussion. 🙂
@kota1 REW may be free (or a donation), but it is not easy to master if you’re not familiar with acoustic measurement taking. It’s all I can do to READ a graphical report, much less create one. I have purchased the Umike-1, downloaded the software, and managed to take a single measurement, a week went by, and now I’m starting all over again. I’ll get there, eventually. I was helped by those who responded to my ‘From Whence comes soundstage?’ and introduced me to the LEDR test. I learned I was not sitting in the proper spot in my room. If I could be comfortable straddling the arms of both my recliner and couch, my head would be in the perfect ‘sweet’ spot.