Acoustic treatment question: do you agree with Dennis Foley that $46k to $65k is required?

It is a matter of doing things right.  I know of a system where the dealer removed much more than $50k in treatments from a client's room to get it to sound right (there was a whole room on the side that stored the massive quantity of tube traps, etc).  I heard a dealer room that had been specially designed and treated by "experts" that sounded terrible (this was during the live-end, dead-end era of treatment).  Among the better rooms I've been in have been rooms with very minimal treatment (mostly decorative wall hangings, book cases, etc).  In sum, among serious setups, I've heard more rooms that sounded dead from overtreatment than I've heard rooms that were undertreated.  

By far, it is MUCH more important to get the placement of the speakers right.  This is actually much trickier that most people think, and one can experiment for a really long time before the right placement of speaker, listening chair and furnishings is accomplished.  But, when it is finally achieved, the results are usually better than one gets by stuffing the room with absorbing panels, diffusers, etc.

At an audio show, a manufacturer, I believe it was GIK, had a very impressive demonstration of room treatment.  They booked two identical hotel rooms, and treated one room with their products, and had the other room untreated.  They set up identical systems in the two rooms.  One could listen to something in one room then hear the same selection in the other room.  The treated room was NOT stuffed with treatment panels like I've seen in some audiophile system, so the room looked like something someone could realistically install in a home.  I liked what I heard, but of course, it was not just the products but also the expertise of the people doing the setup, that made the difference.  

I am certainly not suggesting that treatment is important and helpful.  I am merely cautioning against the "more the merrier" approach or any kind of formulaic approach to treatment.  It is really a quite painstaking procedure that is quite hard to do because of the natural bias (hopefulness) toward thinking that any given addition is improving matters.  I don't know of any really good procedure except careful trial and error.  

A friend added some modest treatment to a small listening room (corner traps and diffusers, and absorption at the first reflection point).  An industry expert that has heard thousands of different rooms around the country is a friend of his that came over to help out with the room.  We were told to close our eyes while the expert performed some alterations which we then commented upon.  To our surprise, the sound improved when the first reflection point absorbers were removed.  I had thought that this was a basic thing that almost always helps, but, he said that while it usually helps, this is not always the case.  The next surprise was when he leaned against the side wall to damp some resonance--again that turned out to hurt the sound (certainly not my expectation).  The best thing for improving the sound turned out to be opening a closet door at the back of the room which acted as a sort of bass trap.  The point of this is not that this or that treatment works, but that it is nearly impossible to make any sort of generalized recommendation--proper treatment involves careful listening and application of products or practices after trying them out.