Placement of absorber panels in our bandroom

Hello all, I have been lurking on this forum for quite a while an have found loads of valuable information. Thanks so much for that, this place is an absolutely awesome resource! I turn to you with a very specific problem/question that, despite of all the research I performed, I have not been able to find a conclusive answer to. I hope I picked the correct sub-forum to post this. Let me start by giving you some background information. We have this little room (length x width x height 5,1m x 4,45m x 2,6m) in the basement of a public building that we use to rehearse and record with our band. We are a 5 people band with 2 guitars, drums, bass, vocals playing modern rock. The room itself was built by our predecessors, who used commercially made divider wall panels to create this within a bigger basement space. In the Sketchup drawing this would be the beige walls. The outer material of them is particle board with plastic veneer. The orange back wall and the window side wall are concrete. The band that had the room before us had covered all the wood walls and the windows with thick rugs, had put thin acoustic foam all over the back wall, carpet on the floor and egg cartons on the ceiling. As we were not happy with the sound of the room (it sounded very muffled for the lack of a better description), we now took all of that above down, put in a solid wood (2cm thick larch) floor and built a total of 12 absorber panels. The panels are made with 10cm or Rockwool Termarock 50 (50kg/m^3 density and >=16kPa sm^2 airflow resistance) on wood frames, wrapped in Camira Cara fabric, and are 1m x 62,5cm in dimension. While is was able to find lots of information on the placement of these panels for a control room, my search on how to best place these in a combined live/recording room did not give me any answers so far. Could you provide me with some guidance on how to place our 12 panels for the best possible effect? Thank you very much in advance! Current placement of the instruments/speakers is as follows (can be changed): Martin