Tell us about your acoustic treatments

All the truth in the world ! My corner traps are 2’x2’x8’ they dampen the bottom end like crazy.

parallel walls suffer from flutter echo, that needs diffusers, and first reflection points need absorbers.

does my room sound dead, yup compared to my untreated hallways and kitchen, but not with movies in my room, it sounds just like what is on the screen, too Much of anything is bad. That’s why parallel walls get the fusion first reflection points get absorption in corner traps, simple as that

Good luck with your build, if you want to read about control rooms for recording studios where I got a lot of my information from feel free to go to gear sluts, the studio section will be very helpful

https://www.gearslutz.com/board/studio-building-acoustics/

All of my corners are treated with bass traps from floor to ceiling and one behind the rack on the front wall.I may add diffusers in the future.
I did move them all around the room at first and listened.The biggest and most positive effect is treating the corners where they meet the ceiling.

Ironically tube traps can hurt the sound when placed in the corners. Sometimes you have to put them away from the corners. Throw away the User Manual.

Primacoustic panels for ceiling, front wall, side walls and back wall. Thick area rug covering most of wood floor. No rack of gear between the speakers. No TV between the speakers. No coffee table in front of listening seat.

Mpingo discs, Tube Traps set up using SPL Meter and test tone, tiny little bowl acoustic resonators, Skyline 🏙 Diffusers, resonating wall outlet covers, no CDs or other media in room, crystals in room corners, DH Cones as Node Dampers, Blue/Green Meanies, Quantum Temple Bell 🔔