So, its that time of the year again, with the cold and rain setting in, and eventually snow, I put away all the toys for storage in my pole barn and am heading back inside for winter hobbies. Last weekend I started gutting the basement (unfinished wall studding in the center, some drywall, rough flooring etc) and ripping down the insulation in-between the floor joists. The amount of mouse .....eh.....stuff is just unbelievable! (Went all around inside and out and sealed everything up). So, what im getting at is there's a room, probably built 30 years ago when the house was built, its 12 feet long, 8 feet wide, and 7 feet tall (these would be finished dimensions) walls A and B are concrete blocks, C is studed with 1/4 inch plywood, and D is plywood with no studs. My goal is to get into DIY audio, experiment with building small (3-7 inch driver bookshelf speakers) and building my own amps, tube and solid, starting out with cheap beginner kits and working my way up, and have plans for a diy turntable. I'd be in a recliner , speakers on stands 5-6 feet out, a diy powered 8 inch? Sub, and behind them would be shelving with all my diy and a few already made speakers I could rotate out and play with, in between the two shelves would be the equipment rack with multiple sources, dacs, tuners, amps, turntable preamps etc that can be swapped and played with. Is this area too small? I ask because if I keep it, I'd brace wall D, spray foam everything except the floor, then.....well, I'm not sure, would putting up drywall over the spray foam only to do acoustic treatment make any sense? Or do I forget about that room, rip down the walls and build bigger? Again, this would be for a diy bookshelf collection I plan to start building with my mother to spend as much time with her as possible before she leaves this world, and to see what a ribbon tweeter sounds like vs titanium, or tube vs. Solid, preamp vs amp. As it would be small, id like to think I can get by with a few quality watts (cheaper) then needing massive power. My reference system in the entertainment room, when cranked, in the seat, using a app, reaches 85 db peaks at 8 ft from the speakers, so, honestly don't think im looking for 90+ as it would likely become painful (as well as possibly permanent) FWIW I have been searching, but everything shows up higher ceilings, and no mention of sprayfoaming the surfaces. As always, I look unto the people for advice, guidance, suggestions, and ideas!