Greetings
I have open book shelves on my back wall. They hold my technical books and years worth of audio magazines. Also a few diffuser/absorption panels and record cabinets.This has worked very well for me. I will add 2 bass tube traps soon. At the moment I prefer diffusion on my back wall. I’m 99% done with my room, not sure when I’ll get to the last 1%.
My head is 6 feet from back wall.
Maybe repositioning your CD’s in a random pattern might help? 6000 CD’s my goodness. Good for you.
Joe Nies