Here is mic that works well.You really need a calibrated mic and REW. Testing various positions with Audyssey will not be effective and at best will be extremely time consuming. If you get a calibrated mic and REW you can probably test a combination of 4 locations in less than 2 hours once you learn how to use REW.
I guess you ended up doing exactly what you were trying to avoid doing when you asked your original question. Oh well... 😣I just ordered the UMIK1. I'll try to calibrate my Audyssey mic, and if it works I may end up selling the UMIK1.