Thanks for the help guys. I will try these one at a time when i get a chance and see what helps.
I guess i should have labeled this thread nasty slap "ping". I know when i clap in other rooms i hear an slap echo. This is a different sound altogether. Really weird.
I have a set of first reflection point absorbers from realtraps, but they do nothing for this sound. I removed them a few days ago thinking maybe i had my room overdamped.
May try to get some insulation and make some DIY rolls to set on top of the crown molding. Does it matter what R value? What have you guys used to roll them up in? Some kind of black fabric would work best visually. I could have my wife sew some tubes and stuff them, i guess.