In-wall insulation is best, as I understand. In my house, my listening room is in a 100 year old part of the house and is without any insulation anywhere (also makes for a chilly February!). We were planning to have insulation blown in but were then advised that it settles. When we replace the cedar shingles (if the economy improves), we'll have insulation affixed to the exterior, although that wouldn't help with acoustics, I do not believe. Fortunately, my wife hasn't complained about the bass traps and acoustic panels in my room. I work with a woman whose husband is employed by a large audio company, and he gets whatever equipment he wants. She told me, however, when he wanted to install acoustic panels, she told him, "No." Eeck!
800 LPs, Wayner. How do you keep them stored? Also, what do you have covering your tables? It looks a lot better than the folded beach towel that I have covering my AR EB-101.
You have a good looking room, Wayner. Great system(s), too. I'd love to hear your Focal JM Labs.