Regarding tapestries and rugs and such, I have a heavy, very coarse weave cotton/jute 4'x 6' rug (oriented in landscape mode) hung on my front wall above the rack and behind the speakers, and about 3/4" from the wall, and what a very nice difference that made. Tended to absorb some of thehf reflections, and also act as a diffuser so the sound doesn't sound muffled, but front-to-back slap echo was hugely reduced and the soundstage is enormous now.
I also have many of the tri corners and the wall/cieling corners treated with the older 8th Nerve .
Too many of these though, I'm sure would deaden the room too much, and if I hang another one, it will be on the rear wall behind my listening chair.
I still have a couple of GIK panels and some diffuser panels for the final tuning once I'm ready for that, but as I just moved my Cornwalls into the listening room, I may have to rethink where those will be most effective.
-- Jim
Jim Rebman -- recovering audiophile
Equitech balanced power; uRendu, USB processor -> Musette DAC -> 5670 tube buffer -> Finale Audio F138 FFX -> Cain and Cain Abbys near-field).
s.e.x. 2.1 under construction. Want list: Stereomour II
All ICs homemade (speaker and power next)