Question: Sound Treatment behind the Listener?

There is a rule-of-thumb (a formula in acoustical engineering terms) for how far one must be from the wall behind the listening position when using diffusion rather than absorption. I didn’t bother to memorize it, as it told me I couldn’t use diffusion on that wall, my currently situation requiring me to sit too close to be able to do so. I'll bet a Google search will lead one to the answer.

With approximately 8' behind you to the wall, the sound level is only attenuating 3.52dB, plus whatever the absorption coefficient of the building materials (ie CD cases are which is probably very low), and another 3.52dB attenuation on the reflection. I do not believe that is near enough. I would be shooting for no less than 10dB if not 15dB. The only options are increasing the distance (which is probably not an option), or adding sound absorption material0, which can achieve that.

@ozzy I'd be curious to hear what GIK says. That's a great service they provide - it was somewhat of an education to me in terms of the information they provided (and why). 

The best situation is to have no wall behind the listener. An open concept situation open to the rest of the house. The rear is then open between various rooms. This keeps reflections as late as possible and fractured as much as possible. 

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