First thing I recommend is with only the things that have to be in the room play and finalize speaker position. You cannot position speakers in a room with room treatment. You will find that when you get the best overall sound the room will have the least negative effect on the sound. Then one by one you can bring in acoustical treatment to fine tune the sound.
You want to be very careful what materials you use to control the rooms reflections so it does not not over damp the room and worse cause comb filtering effects ( large peaks and valleys in the frequency response). Most absorptive material will absorb at certain frequencys and reflect at others. I use very light material to only delay reflections and not to absorb them.
Defuser's are also a good thing to use, so as not to absorb sound but to eliminate slap echoes.
I believe in keeping the front wall reflective, NO absorption, defuser's are ok, with very slight absorption on the back wall. Side wall reflections are again best addresses with defuser's.
I suggest installing one at a time so you can hear what each one is doing and where it is taking you acoustically, until you get the desired results you prefer.
It takes time and patience
As far as bass modes, those are very difficult to address. Your room dimensions show bad ratios and will have many bass mode issues. At 50hz, 75 hz, 101hz, and 150hz. Bass draps do little to nothing. Only two options is alter the room dimensions ( build a room with in the room) or helmholtz resonators. These must be built and tuned specifically to the rooms modes.speaker placement will definitely effect this too, so make sure you do that first to try and minimize those room modes. Any other questions feel free to ask. A good size area rug or simply carpet on the floor is also recommended to treat floor to ceiling reflections.
You want to be very careful what materials you use to control the rooms reflections so it does not not over damp the room and worse cause comb filtering effects ( large peaks and valleys in the frequency response). Most absorptive material will absorb at certain frequencys and reflect at others. I use very light material to only delay reflections and not to absorb them.
Defuser's are also a good thing to use, so as not to absorb sound but to eliminate slap echoes.
I believe in keeping the front wall reflective, NO absorption, defuser's are ok, with very slight absorption on the back wall. Side wall reflections are again best addresses with defuser's.
I suggest installing one at a time so you can hear what each one is doing and where it is taking you acoustically, until you get the desired results you prefer.
It takes time and patience
As far as bass modes, those are very difficult to address. Your room dimensions show bad ratios and will have many bass mode issues. At 50hz, 75 hz, 101hz, and 150hz. Bass draps do little to nothing. Only two options is alter the room dimensions ( build a room with in the room) or helmholtz resonators. These must be built and tuned specifically to the rooms modes.speaker placement will definitely effect this too, so make sure you do that first to try and minimize those room modes. Any other questions feel free to ask. A good size area rug or simply carpet on the floor is also recommended to treat floor to ceiling reflections.