James - this is certainly an interesting discussion. I would agree that a room that is too lively is better than one that is too dead - to a point. A lively room will sound better at lower SPL's, but once you reach a certain point, the sound becomes all reflections with no focus. A dead room will not have those issues - at high SPL's.
What's your thoughts on diffusion? Would you suggest diffusion at first and second reflection points? If not man made diffusors, perhaps something more natural and aesthetically pleasing like a large pot with bamboo sticks or large silk plants?
Then, we also have the question of the listener. Some (many) listeners are very sensitive to high frequencies, perhaps because of tinnitus or something similar.
We also then must look at the asymmetrical shape of most rooms which ultimately affect time delay. Even rooms that people think are symmetrical are really not. Have you seen bulges in drywall? Warping? One size of the room that is longer than the other? The list goes on...
What about standing low waves, especially mid bass? Corner traps can be very affective at dealing with it. I think most people have trouble dealing with bass than higher frequencies in their room.
If there was any doubt as to whether a treated room sounds better than an untreated room, those doubts were put to rest if anyone attended the Resolution Acoustics demo at Axpona. Resolution Acoustics had two rooms - one treated, one untreated. They had the same speakers in both rooms and the same amps. They had the same preamp/source delivering to both sets of amps the same music at the same time.
Jim Hannon of the Absolute Sound said:
Resolution Acoustics, one of the five Most Significant Exhibits
This patent-pending diffusion and absorption system effectively took the room out of the equation when compared with an untreated room with an identical system (Sonus faber Stradivari speakers, Pass Labs electronics, Meitner MA-1 DAC, and Wireworld’s flagship Platinum and Silver Eclipse cables). The Resolution Acoustics’ solution leaves the directed wave from the speaker dominant while weakening the reflected waves. I thought there was a huge difference between the rooms, with far greater clarity and focus, as well as no bass boom or smear in the acoustically treated room.
Jonathan Valin of the Absolute Sound said:
In a fascinating demo, two pairs of Sonus faber Stradivari, both driven by identical Pass Labs amps and both sourced simultaneously from the same server/DAC, were set up in adjoining identical rooms, only one room was untreated and the other was, with wall and corner treatments designed by Bart Andeer, founder of a new company called Resolution Acoustic. Andeer is a genuinely interesting fellow, a ship captain and marine engineer with a lifelong interest in hi-fi and acoustics. As you might expect, in the Andeer-treated room (see photo above) the Strads sounded considerably better damped and more neutral, with far more ambience retrieval and soundstage space.
Jason Victor Serinus of Stereophile said:
One of the most revealing demos of AXPONA/AudioCon 2015 was sponsored in two adjacent rooms by Bart Andeer's Resolution Acoustics. In one room that had no room treatment, an excellent system that included Sonus Faber Stradivari loudspeakers, Pass Labs electronics, Meitner MA-1 DAC, and a Mac mini played a piece of music. In the next room, complete with room treatment custom designed and placed by Andeer, the exact same equipment in the exact same location played the same piece of music via a signal split at a Pass Labs XP-30 preamplifier.
I had expected greater bass control in the treated room. What I did not expect was how much richer, fuller, focused, and more refined the music sounded, top to bottom. Even the highs were rounder and more colorful. I've never experienced a more convincing demonstration of what optimally chosen and judiciously positioned room treatment can do.
So at the end of the day, I'm not sure I agree about room treatments. As they say about real estate, its all about "location, location, location". In audio, its all about "the room, the room, the room."
YMMV.