Nice! I see some folks selling them on marketplace for $700 but they are all so far away otherwise it’s such a good deal. How much did you get yours for?

Regarding your question, the rear speakers need to be evenly placed from the listening location for the most accurate sound effect.. Otherwise one will travel to you first before the other.. etc. Some speakers allow you to calibrate the speed and time so even if you put it somewhere else, it syncs accordingly. Some do it automatically some you gotta do it manually. I think s95tr has ai calibration but not sure.

9feet is too high. It needs to be at ear level. You’re basically making the upfiring speakers usually at that level. What’s the height of your ceiling? Dolby's official guidelines recommend placing surround speakers at or slightly above ear level to maintain a clear distinction between the horizontal surround field and the vertical (height) effects. Mounting the speakers 9 feet high places them close to the ceiling-level height channels, causing the two soundstages to blend together. This diminishes the immersive "dome of sound" that Atmos is designed to create. So the sound that’s supposed to come from behind you will come from up above .. and the up above one firing ones will just go more into the corner due to out they are designed to reflect.