I just want to add--
Many folks hear "room acoustics" and immediately envision fabric panels and/or exotic diffusers. Very few persons pursuing these items have a complete understanding how/when/where these are required. This only perpetuates the mystique surrounding acoustics - the results are often unpredictable.
Room acoustics oughta be extremely important to all audiophiles. Duh.
The problem is that there is so much disagreement on what constitutes "good acoustics". So it continues to be written-off as a matter of taste, and not science.
Another problem: Very few audiophiles have actually experienced optimum acoustics! Switching speakers or components is easily tried, and takes very little time, and is fully reversable. Changing acoustics often requires a serious commitment and time, and does not respond well to the trial and error approach that is the accepted practice for all other other areas of our systems. Poor understanding-->poor application-->mixed results-->limited priority.
Individual tastes notwithstanding, I largely believe that disagreement is because so many are looking at old criteria (reverberation time, shape, dimensions etc), and trying to apply the same set of band-aids to every listening room, while ignoring criteria that can be universally applied.
Research in recent years has revealed the most useful criteria are about reflections--timing, frequency spectrum, density, and direction all reflections. These factors are more critical to fidelity / illusion of reality than (typical) reverberation, etc.
Very early reflections (<~5 ms) are bad. The brain can't seperate them from the original. The result is shifiting of image, loss of transients, etc. The source of these can be the speaker itself (cabinet, driver frames, etc), nearby objects & furnishings, walls, etc.
Early reflections (~5-10 ms) are hotly debated. I prefer to kill or redirect them whenever possible. 'Problem is that domestic size rooms make them unavoidable. The impact of these reflections depends on how they are presented to the brain in terms of spectrum, direction and level. They can add spaciousness to sound, but can also smear imaging, etc.
Late reflections (somewhere >15-50 ms) are generally useful, and are often diffused and attenuated enough by the stuff in our room to not be a problem. They can help widen sweet spot without hurting imaging, and give the illusion of envelopment.
Very late reflections (50+ ms) are only desireable if diffuse, and/or attenuated in level. This will happen naturally in most cases. Typically they don't exist at all in domestic size rooms, as they only result if a sound bounces several times before ever being "heard". Any of these that exist would be likely be buried in the reverberation or noise floor in a room.
Small rooms are the most challenging because the reflections that reach the listener are invariably too soon and too strong to be beneficial . . . unless your only need is "make it loud".
Recent research has shown that the brain can learn what to disregard from a system. That's all fine & dandy if I never have visitors, and I don't mind missing out on a lot of sonic information that's buried by the room sound, and if I don't mind listener fatigue that results from such an arrangement. That arrangement also is, by definition, not High Fidelity.
Wow . . . shoulda saved this rant for a new thread. 'Thanks for reading.
-- Mark
