I feel everyone's pain, been there, done that, have the t-shirt with speaker positioning.
In my case I struggled integrating a new pair of speakers into a 24 x 26' room with pretty awful acoustics. I got the speakers sounding really "dialed in", then had to start all over, after adding a pair of sub woofers.
The room added a single bass tone (no matter what notes the bass players were playing) that was about as loud as the sub woofers. As I got the bass under control, eventually placing 10 bass traps around the room (with the help of REW and a calibration mic), I had to re position the main speakers to once-again get that "performer in the room" sound stage.
I eventually "got it" and have left well alone since then.
In my case I struggled integrating a new pair of speakers into a 24 x 26' room with pretty awful acoustics. I got the speakers sounding really "dialed in", then had to start all over, after adding a pair of sub woofers.
The room added a single bass tone (no matter what notes the bass players were playing) that was about as loud as the sub woofers. As I got the bass under control, eventually placing 10 bass traps around the room (with the help of REW and a calibration mic), I had to re position the main speakers to once-again get that "performer in the room" sound stage.
I eventually "got it" and have left well alone since then.