I have fairly recently been in a room designed by Art Noxon of Acoustic Sciences Corporation, and build using his products. The walls are double layers of sheet rock with Wall Damp constrained-layer damping between them. I rapped on a wall with my knuckles, and the sound produced was like knocking on a brick---non-resonant. In other words, the walls produced no sound of their own (right, I know; don’t knock on your walls when music is playing ;-) . That’s "one" approach, another is to "tune" your walls until the room sounds "good" to you on any given piece of music. Sure, you may then have to "retune" the walls for another piece of music, but what price musical pleasure?
All the wall/wall and wall/ceiling intersections of the room are fitted with ASC Acoustic Soffits, to absorb room mode standing waves/resonances. Because of that, the room is very "neutral", not imposing its’ own sound on that of the source material and hi-fi system. That’s "one" approach, another is to let those standing waves roam free, in the name of not "killing" ANY vibrations, mechanical or acoustic (’cause, you know man, music is vibrations). You may then take measures to "corral" those acoustic vibrations, to produce from the recordings you are playing the sound YOU want. It’s all about you, man. J. Gordon Holt was right about the generation of audiophiles that followed his.
